My experience, is that the ones made in the 1970s and 1980s had crap quality.
I watched this movie, and think it very much deserved the Oscar, but the character rendering was a bit “scruffy.” The environment rendering was great, and it looks like they optimized for movement, in the characters, which was a good choice. Once I spent some time, watching, the rough rendering didn’t matter.
I had a similar experience, watching Avatar. At first, it seemed like a cartoon, but I quickly became immersed, and the fact it was rendered, didn’t matter.
I read, somewhere, that the movie is being re-rendered. I think they may have the money for that, now.