Fox is a confusing character to analyze. I've always held he was top 10 in Smash 4, but is way better in theory than he is in practice.
I agree with this, I think at a top level fox requires probably more precision than any other character in the game.
Mistakes hurt fox a lot, and its easier to make mistakes due to the difficulty of the character.
Thats a good thing though, it stops fox being spammed by everyone which makes him boring for us and everyone learns the matchup inside out.
I've always felt that making the best characters also the hardest to play is really good game design, unfrotunatly that hasnt really been the case in smash history but whatever.
when you are playing in the zone with fox, its a beautiful feeling.
He does lack in 2 areas though, foster is right he does lack that throw setup that the other top characters have. I've found that up throw can sometimes put you in positions to get an uair kill or to pressure them with uairs which can lead to getting a usmash punish on them, but against a really good player they'll just di out over the stage, going out and around back to the ledge, taking advantage of foxes other weakness, which as mentioned is his lack of any real offstage game.
I've found that focusing on getting really good at reading and punishing your opponents ledge getup options can make up for that lack of offstage game though. jumping up and down with an nair ready can actually beat almost all their getup options, if you read a roll from them you get an usmash if you are on the ball and a dsmash if you are a bit slower to react, you can dsmash them in the 1 frame ledge grab vunerabiliy depending on the character.
If the oppoenent does a regular getup (pressing forward on the ledge) there is a small window, I think 2 frames? where they are vunerable at the end of the animation but cant act yet, fsmash can hit that window pretty easily since it lingers and thats usually a kill for you. some characters will drop off the ledge and double jump onto the stage with an aerial, depending on the character you can beat it out with an fsmash. also standing at the edge can bait out getup attacks, you can walk away from the attack and then fsmash back at it (probably doesnt work well against top players who've figured out that getup attack is a **** option and wont do it)
Also with customs on fox does actually get an offstage game, laser 2 can take away double jumps for occasional gimps, and then there this...
anyways if you couldnt be bothered reading my ****ty long wall of text, take this to heart.
Fox in melee used to be considered the best in theory but not in practice because he was too hard to use.
As time went on and people got better at the game and better at fox, that sentiment went away.
Stick to fox and you'll be rewarded in the long run.