I think it's a little of everything. Not every movie is made with the same people who make the CGI effects so all the outcomes are different. Sometimes CGI may look good 10 years ago or 10 years from now. Personally, I think they have gotten better in their own "unique" way. Like, you can tell CGI is used most to express more detail in visuals rather than back then CGI, specifically in Jurassic Park, was great in some scenes where they did close up's on the dinosaurs but in other scenes you knew they were fake.