[falserum]

Process is (laymans understanding):

1. you observe a galaxy doing something strange

2. whatever it does, you add just enough dark matter to account for that behaviour.

Such process seems fishy, because it can explain ANY observation.

If we would go back 130 years ago where GM was not a thing yet, and GM would be competing with DM theory, occams razor would point to DM, because it is simpler one - it fits with newton nicely.

(not an expert though, just repeating stuff I heard on youtube; I’m happy that experts work on all kinds of angles)