It's a simple reason for why practical effects were abandoned for CGI: film crews are unionized, 3d animators are not.
The rhetorical lengths some people go through to avoid talking about the actual, material reasons for these things. We are in general much more interested in just lamenting society, instead of complaining.
Representing animation artists, writers and technicians since 1952.
Now, that only covers a small number of studios. So, of course, not every studio can be part of it. But it is a union and it does drive some of the industry standards and expectations.
That makes non-union labor cheaper in comparison.
(Full time colorist here)