A2ZOMG, Uair and Bair aren't enough in this MU to hold his own. Wario does not win with range, he wins with mobility and mix-ups. Characters that can wall him do it to do raw range or ridiculously frame traps, Marth and Peach, gain advantages on him because of that and grab releases. Mario can not effectively take advantage the same way other characters can.
U-tilt, F-tilt, and AutoJabs control Wario extremely well, and when Wario is at KO damage (or if Mario is in the lead), he has to really fear U-smash. They have the range and frames to make it extremely difficult for Wario to get in safely. Not having a grab release I guess sucks, but this doesn't change the fact that Mario does wall Wario really well. With a grab release or a stronger B-throw, Mario would win about 6/4, which is simply a statement that Mario's damage dealing is by far more consistent.
If Mario's tools were better and more effective, he would win the MU. Because then his tools would be more effective against the character, then why does he lose the MU? Because Wario can kill better? Wouldn't that mean his tools are better in this MU due to him being able to kill better and get the damage up to that point.
Uh, Wario just has F-smash. Granted F-smash is really good. In terms of being able to rack damage and control the pace, Mario clearly does it better, just he has to legitimately outplay Wario for the kill. Winning in fighting games is not always guaranteed by being able to control the pace alone. Controlling the pace is simply one of the more important aspects of matchups. Wario wins however not because he's in control. He wins through essentially random brute force.
Mario will fall out on Brinstar due to the layout, acid hazard, and Wario being able to move as freely as he wants. Closer blastzones are better for Wario due to his fart, his better maneuverability is a tighter area with the platforms, and doesn't care for the stage hazard, heck if Mario hits the acid it can be a free waft.
Lava is MUCH better for Mario than it is for Wario. Mario can camp with a projectile on Brinstar as much as he wants and cover wherever he wants. The platform layout is also MUCH better for Mario because his platform pressure is one of few that is existent on that stage. Fullhop D-air covers the top platform. SH D-air covers the low platforms. And you can frametrap escape options easily after a blocked D-air. Mario can Cape Stall to avoid the lava easily in most situations. Waft is decent, but a limited resource, and Mario benefits more from the fact that U-smash and B-throw kill earlier. Waft kills early on any stage, even Japes, so getting killed by it on Brinstar isn't a big deal.
I'm not saying that the Uair's were unavoidable. People make mistakes and punishing mistakes is a big part of any fighter game, but you make it sound like Uair is such a bad punisher that it shouldn't be landed. Honestly a lot of times you get hit are off mistakes if you wanna dig into theorycraft but let's not do that now.
U-air is a bad punisher. It has crap range, and its application is generally very telegraphed. You have to make a very blatant mistake to actually get hit by it, and that's the facts. Thus it matters little in matchup discussion.
Getting hit by basic pokes and occasionally getting caught off-guard by blitz approaches isn't a mistake. There's also situations where some slow moves are more useful than fast moves due to their synergy with the threat of faster moves. Wario has NOTHING to force you to get hit by U-air. You're either doing something dumb that leaves you really open (playing a character like Falcon or Bowser might count, given they have very very few landing options), or you're not getting hit by it.
This is my point. Some moves you have to either make a read or they have to make a mistake for them to land. This **** happens and you can't just say "this shouldn't happen." I got out of Pound 5 pools 1st round off a really good Fsmash read.
Again, this is an example of being gimmicky enough that it does not matter in matchup discussion. You are by far more likely to win matches by focusing on more practical things. There's actually non-gimmicky ways to land F-smash, but the standard tactic where most Mario users grab bait into F-smash is so 2009.
So he has ONE move going for him. So Mario dominates Wario tool-wise, has better damage racking, walls Wario, better air game, better ground game, and better tilts and Wario just just Fsmash going for him. If that's all he has going for him and he still has some advantage then Mario must be a really bad character.
You're taking this so ridiculously out of context. You can't make lazy assumptions like that. The point is despite the fact Wario has a lot of moves with extremely bad range, priority, and below average speed, F-smash alone is extremely good and changes what the game is about. It has to be respected, since it does massive damage and can kill. This coupled with Wario's mobility gives him slight adv because you have to legitimately outplay him to get the kill, since a screwup results in getting F-smashed. However the advantage Wario has on Mario is extremely slight, and lost on counterpicks. The facts are Mario does in fact outdamage Wario easily, and on Brinstar, where Wario's F-smash almost never comes into play, it's Mario's advantage easily, especially since Wario cannot effectively aircamp against Mario on Brinstar.
Honestly a lot of Melee Falco's matchups are analogous to what this matchup is like. He dominates the **** out of everyone on a tools basis. He just has what is probably by far the best damage dealing in the game, in his ability to just always be able to touch you when you don't want him to touch you. And yet Marth, Fox, Peach, and Jiggs beat him slightly. Why? Because grabbing him (or even just putting his feet offstage) is extremely good and changes what the game is about. Even Dhalsim in Street Fighter IV has bad matchups, despite the fact he is one of the best characters in the game at scoring free damage and being in control.
Yes Snake dies at lower percents just like everyone else, but he has a really strong, reliable kill move with broken range and probably still dies at pretty high percents. Mario has nothing to match up to that. Other heavy characters like DK don't have a move as reliable and therefore aren't good on Halberd. Although that's enough to prove your idea wrong, I'm gonna disregard it. What also makes him stupidly good on Halberd is how his recovery is increased dramatically. Edgeguarding Snake is one of the best ways to rack up damage. On Halberd, he now has the option to avoid a lot of damage by recovering through the stage. Talking about Mario specifically now. He has lost a big way, possibly the best way to rack up damage on Snake and he's gonna die from Utilt at 90%. What does Mario possibly have that can match up to that?
Snake's U-tilt is super overrated as a "reliable" kill move. He ultimately requires you to **** up to get hit by it since his juggle options are ***, and that's the way it is. Recovering through the stage sucks *** because it means you can't walltech to save yourself when C4 recovering. And he's almost never going to actually be in the position where he can avoid your edgeguards by recovering low anyway. You're theorycrafting mad hard. Seriously man, do you even play this matchup? You obviously have zero Halberd experience given the things you're suggesting that make Snake better on Halberd. He only gets slightly more annoying grenade camping. The stage is actually not favorable for him at all in every other way possible.
For Mario, killing Snake is GONNA happen if he's careful. He just needs to be patient enough and wait until Snake is in KO range, and then go for simple safe juggle setups into his Smashes. This is why Halberd is more beneficial to Mario in the matchup. His kills aren't random, and mathematically they benefit more from the small boundaries. Also the Halberd laser while minor is technically more beneficial to Mario if well positioned because it will interrupt Snake's grenade camping while still letting you fireball camp.