He still has a very hard time fighting spaces though. Doc isn't really ideal for fighting spaces either. I mean, Shroomed doesn't even use Doc as much as he used to.
Even Luigi and pikachu have better tools than Mario in fighting Melee's elite. Heck I might even throw in Ganon.
Mario has a better chance against Sheik and Peach than those two at least. Against Sheik, chaingrabs her halfway to death and gets guaranteed F-smash out of D-throw no matter which way she DIs. F-smash and U-tilt saves Mario against Peach if you're willing to play a long game.
Honestly, Mario is kinda broken in Melee if you ask me. Ignore that the top 5, Samus, and Ganondorf troll him. He invalidates some characters kinda unfairly hard with his D-throw and F-smash. If the spacies didn't exist, nobody would argue Doc is better than Mario.
Also Mario craps on Pikachu, Luigi, and Doc. Mario just fishes for D-throw against Pikachu and wins once he gets it. Against Luigi you just throw grounded fireballs, throw him upwards, and U-tilt until you're bored. Against Doc you F-smash all day, throw him upwards if he gets close, U-tilt til bored, and B-air gimp him. As I said, Mario is honestly a kinda broken character. A lot of characters can't outspace his F-smash which is also safe on block, his U-tilt juggle is braindead against characters that can't outdisjoint it, his D-throw is just plain dumb, and he also gimps people very easily with ledgedrop aerials.
The Ice Climbers are probably imo the funniest matchup Mario has. One of the best Mario players, Boss, is TERRIBLE at that matchup even though it's so braindead easy for Mario because you only just need to B-throw and F-smash and they can't touch Mario.