This assumes that dark matter exists when there has been no direct evidence of it. The observations demand that the models change to fit the data. Some argue a light touch (dark matter).
Entirely on the contrary. Dark matter is the label given to a set of anomalous observations. The entire problem is that we called it “dark matter” when we should have called it “missing mass”, because that’s what it is. There would be no controversy with the latter name.
Technically, "missing gravity". The mass is inferred, but not absolutely required. (Though it is by far the simplest explanation.)