One story I've heard is that the original Tron was responsible for a lot of this. They originally tried to use computer graphics for many of the movie's effects

One story I've heard is that the original Tron was responsible for a lot of this. They originally tried to use computer graphics for many of the movie's effects, but it proved to be way too expensive and time-consuming using the technology of the time. So they ended up hand-animating and rotoscoping most of it. The hollywood studios deemed the CG a failure and were scared off of it for a number of years following. So computer graphics didnt get as much adoption as it would have otherwise throughout the 80s. Also many, many movies still use practical models in addition to CG. It's just that now movies can blend both techniques to use whatever is most appropriate for a given shot. What is rare now are movies that use no CG at all.. even things like Mad Max which are touted for their practical effects utilize a TON of CG work.