MOND may be a fringe but wholesale support of Dark Matter by mainstream physics has always seemed cargo culty to me. Over a hundred years and we still don't have a good understanding of dark matter.

A red flag to me is how there doesn't seem to be large amounts of dark matter in areas closest to us where we can see best. It's all this far off enigma. And at least originally the theory existed to explain why the laws of gravitation didn't line up with visual evidence.

To me "half the matter is invisible" is just as outlandish as "maybe our math is wrong about gravitation". I don't think enough of the community questions the dark matter theory.