"dark matter but not as much" is still an improvement if you replace it with something better. If MOND predicted these observations and LCDM didn't it's reasonable to say that it is better.
Yeah that's fair. I guess it could also explain why DM has been so hard to pin down, if both MOND and DM are true then there might be DM candidates that have been unfairly ruled out.
I do think it significantly hurts the (more philosophical) argument that MOND is simpler or has fewer parameters than DM though.
So the ongoing problem with LCDM is that the parameter space for allowable particles keeps getting pushed back. We keep falsifying classes of potential particles that could be WIMPs. MOND+ some standard model-adjacent particle (like say right handed neutrinos), if we can have a phenomenological estimate of how much of them should exist, would at least be credible on account of having a constrainable set of parameters, whereas the density of WIMPs in normal LCDM has no constraint besides the same measure that we have to infer its existence (gravitation)
