[nimish]

This is maybe half true. Dark matter is required to explain these under the current lambda-cdm model, but the behavior of galaxies is not evidence for it in a constructive sense. It's only evidence that the current model is untenable.

Galaxy rotation curves are better explained by applying general relativity without the severely restrictive assumptions required in lambda cdm. You don't even need the full thing, just the first order linear approximation that allows for gravitational waves (and thus is causal), as Ludwig showed a few years ago. You need at least this because gravitational waves exist, and those cannot occur in the singular newtonian limit used mostly for convenience.

It doesn't take much to then question the need for dark matter as if it is compensating for poor models in one case, it probably is doing the same in others.