In theory, a near-infinite, ever-changing series of Pac-Man maps would be incredible. Adapting to the different layouts on the fly, coming up with strategies to approach each different map - it's something I'd love to see high-level Pac-Man players give a shot.

But we'll need a far better platform to do that on than this.
The World's Biggest Pac-Man is also the most flawed, both for some extremely questionable decisions from the developers, and... well, have you looked at the mazes?

It's not entirely the users' fault, honestly - the user interface and tutorialization could have been far better.
The fact that when you start off a maze, the playing field is completely blank undoubtedly is what causes so many maps to be devoid of walls, leaving Pac-Man and the ghosts wide open... which is a battle Pac-Man loses almost invariably.

There are other checks I wish the game had the foresight to make: checking for dead ends, checking that all dot paths are only one tile wide, checking that Power Pellets are distributed with at least some semblance of evenness. All of these are issues that plague the majority of maps found in The World's Biggest Pac-Man.

Maybe it would be a little too stifling if the game had a hard check for these things and prohibited users from uploading maps that don't meet these criteria. After all, what if someone's intention was specifically to make an awful map for people to hate?

But I doubt that that was the intention of most people. Rather, I think that most people don't know how to design good Pac-Man levels, and that The World's Biggest Pac-Man completely fails in teaching people how to do so.
There are zero tutorials or breakdowns of what goes into a well-designed, interesting but fair Pac-Man maze design, and thus people are bound to just do whatever comes to mind, without considering if what they made is actually fun to play or not.

As for the reason why? I think The World's Biggest Pac-Man just straight-up doesn't understand Pac-Man.
Both the tile system and maze size is completely off-scale with the original arcade game - and even if you were to argue this as a deliberate choice in order to make it easier for people to design levels, no other aspect of The World's Biggest Pac-Man indicates that the original game's design was given any meaningful thought when translating into this sort of endless design.

Pac-Man cannot make his signature tighter turns as very clearly outlined in the Championship Edition games, meaning that ghosts often close up on Pac-Man when turns are involved.
The ghost AI are extremely questionable, and have none of the deliberate AI sensibilities found in the original game besides "Blinky is the most tenacious one, I guess".

There's a lot of very shoddy, half-baked measures to make sure that players won't absolutely bleed lives from the atrociously designed mazes - ghosts never speed up, and Pac-Man is always faster than them when travelling in straight lines; the power pellets last a consistent duration of time, which I think is the single most deliberately well-designed choice to come from this game; and the bonus fruit progression system means that if you can hypothetically grind your way up to the key, it might be possible to find yourself in a fairly endless potential for play as long as you spend as little time in poorly designed or otherwise difficult mazes and make a beeline for deliberately easy mazes.

I think The World's Biggest Pac-Man is a framework built by people who don't understand Pac-Man, and a game supported by people who don't understand Pac-Man.
And that's fine. I don't expect the general public to be this pedantic about the intricacies of Pac-Man.

But The World's Biggest Pac-Man tells me not to expect the general public to make a good game that I enjoy.

...so will someone please tell me why on earth i bought Super Mario Maker 2?