This is a bit of an indirect answer, but I watched this not too long ago and it made it seem clear that MOND doesn't work so well, if not in general at least in the case discussed, which seems pretty damning regardless: https://youtu.be/HlNSvrYygRc?si=6on0pD9_jsed9Dlm

I've also heard the bullet cluster pointed out as a strong counterpoint to MOND--I'll let you read the wikipedia page rather than attempting to explain this, poorly: https://en.wikipedia.org/wiki/Bullet_Cluster

As a layman who watches tons of astronomy and physics videos, my general sense is that dark matter is more or less simply a placeholder, such that everything else around it is pretty consistent, but it just represents this unknown matter that we can clearly observe interacting _gravitationally_ with galaxies and other objects in the universe, but otherwise doesn't seem to interact. Whereas my impression of MOND is that it's a set of heuristics that requires a lot of tweaking to work, whereas GR is quite simple and very strongly experimentally verified. But, again, layman