My understanding is that while MOND seems simpler on the surface, it a) is hard to make match observed data (you end up needing dark matter anyways to make it w

My understanding is that while MOND seems simpler on the surface, it a) is hard to make match observed data (you end up needing dark matter anyways to make it work, and it still falls apart on things like the bullet cluster) and b) breaks all sorts of other things in physics that don’t look like they need to be broken (you have to staple new stuff to the side of relativity to keep it all consistent, in some cases breaking conservation). Dark matter looks/sounds hacky and broken, but in general matches real-world data better than the competing theories.