Tetris in particular has gone through numerous tiny adjustments over the years to make it into the game played competitively at the highest level. You might want to familiarize yourself with the existing Tetris versions before trying to tinker with the formula.

I think the answer to your questions is no.

I think breakout hits ala Tetris are less likely with AI, mostly just because our attention will be fragmented.

Quite obviously the percentage of breakout successes will crater, when Tetris came out there weren’t that many game developers, and the number of game developers will probably continue to explode. There will probably be more viral successes, but probably not with the staying power of Tetris.

But I’m sort of defining better here as persistent popularity. By more distributed subjective definitions of “better” the answer again is probably definetly yes, there will be any more opportunities for any one person to think game x is better than Tetris, even if that game never finds broader success.

Maybe like 5% better, but you need like a 10x for the whole world to care about it.