MIA cars are a lot more hit and miss. I have a 2020 MIA one that is good, but it did need some tweaking to get there. To give an example - complaints about chrome trim alignment were a regular occurrence pre-MIC, now I don’t think it even comes up except in isolated cases.
It would be fair to say that MIC build quality is more consistent rather than “better” (Fremont can build a car properly but it seems to require all of the stars to be in alignment). The fact that they are much more consistent does lend itself to being naturally seen as better, if that makes sense.
Beyond that I would echo the general point that the refinement and materials is not commensurate with the price, or the competition. Unlike, say, Apple the aspirational premium we pay is not “felt”. A £30k MG4 I have use of doesn’t feel noticeably worse in terms of interior materials etc and in some ways is better.
If you come in expecting high end Mercedes, BMW or Audi refinement you will be disappointed, but at the same time those marques have interiors that are much more likely to date quicker, I think, as technology and attitudes change.