There is a copypasta for this question, so I'm just gonna paste that:
"This question comes up a lot. There are three main reasons why an individual level leaderboard doesn't really make sense in the context of SMW.
First, at minimum, you have 98 different levels, which is a lot but probably manageable. But consider after all the variations (no yoshi, no cape, small only, all dragon coins, etc.), that number comes to over 1000. Games like SM64 don't have this problem because there's not an analogous powerup system that affects your strategies.
The second problem that comes up is that even if we did manage all 1000 levels, people would actually have to submit to them. 5[?] years ago or so we did have this in some effect, and the vast majority (over 3/4) of it was empty, and most of the submitted times were worse than a top-level fullgame runner would play that level as. If everyone uploaded their own level PBs it wouldn't be a problem but you'll have trouble getting a significant amount of people to do so.
The third and final problem is best quoted by ThirdLavaDolphin: 'The final problem is that those of us who are active in doing ILs for this game really don't care for it to be competitive. The primary motivation is finding and demonstrating new strats. If someone comes along and beats one of my times by a few frames using the exact same strats, that's great, but I'm not going to go back to the level just to shave another frame off if I don't have anything new to add (and smw's mechanics ensure that there are basically always going to be frames to shave off in any nontrivial IL). If there were a number of serious IL runners who want to have that competition (whether or not that group includes me) it might be worth the effort to work through the other issues. But so far pretty much everyone who actually does serious ILs and strat finding just isn't interested, and the people asking for IL boards have been relative newcomers.'"
This copypasta predates my involvement in the community, but I see it get thrown around often. And it makes sense to me.
If anything, I'd suggest using the practice cart and going for Gold or Pink times on that ROM. I think that's a pretty good way of meeting goals in ILs without bogging down the busy pipeline that is this leaderboard.