I definitely feel there is something else going on, but am not qualified to say how. Dark matter seems a heck of a large hook to hang much of cosmology on. Maybe it is real, maybe not.
Time dilation! As time itself emerges from space/gravity, mass and distance could introduce a “time dilation” fudge that cosmologists attribute to “dark energy/matter”!
It may be our lack of understanding of time itself that changes factors of how we calculate the cosmological expansion/contraction and other mass stability estimates.
I too find it funny that we can wrap up our ignorance into a concept and call it dark*(whatever)!