Honestly it really hasn't. XII had over 40 minutes of CGI and so did XIII. The only reason why XV didn't follow suit is because they decided to concentrate all their CGI efforts on Kingsglaive, along with the rewrites, hence the scrapping of CG cutscenes we saw even in 2015. I'm pretty sure VIIR will have 30+ minutes of CG cutscenes.
And same here. I'm just imagining a version of XV where the Altissia segment involved a bunch of gorgeous and action-packed CG cutscenes and I'm getting sad.
You're probably projecting a bit here. (you're right about the 2015 stuff being scraped for the movie though)
Even before all the team-shifting and the renaming, the game wouldn't have anywhere the same amount of CG scenes.
Back in the vs13 days Nomura kept talking about how he wanted minimal CG scenes b/c he felt like the tech was at a point where CG wasn't worth the same as it once was (or rather, he felt like real-time cutscenes were the way to go).
Idk why you though Altissia would be full of CG scenes though. That just sounds like weird expectations you put on yourself.