The time required to create a scene with lots of movement is higher if you have to draw every single frame than if you can adjust and automatically recreate every frame. Either combining both or creating a 3D movie requires a lot of manpower,
I thought we were talking about live action productions, but you're talking about Anime production. I can't say too much about how the Anime industry uses 3D, because Japan isn't as skilled in that department unless they're shelling out big bucks for the few people who seem to be well versed in it. What I do know is that generally you wouldn't normally use CGI in a vacuum. It's part of the shot so you're bouncing back and forth between 2D animation department and the CGI department. Generally speaking, if you have CGI involved then you're planning to mix the two together from start to finish.
the problem is when CGI is used to substitute the drawn animation part even if it means looking bad and when they reduce the number of samples and variations for 3D to a "passing grade".
Right, I can see that being an issue however you can mimic a handrawn style flawlessly in 3D, so I don't agree with that part being a problem. If they choose to use 3D as a main player on the stage, I think that's fine. However, you are very right when they use it poorly to cut costs, but that stands with any production.
Also it's not too much of a matter of "Samples" and "Variations" more so the shading template that goes into the rendering engine that allows it to match styles in the final product from the compositor. Assuming they are using a shading system and not just texturing it, slapping some lighting on it and calling it a day. It often doesn't seem like these productions have an NPR shading system in play and are just winging it so maybe that is what's happening.
Something becomes cheaper when you cut corners, so they reduce the number of hours required for something by hiring less people
Right but this is a problem with the anime industry as a whole. If 2D artists are barely getting paid, then you wouldn't expect a 3D one to do any better would you? With that in mind, it seems unfair to say "It's bad because it's full of CGI" when productions full of CGI exist all the time without notice. Wouldn't it be fairer to say "It's bad because it's full of
bad CGI"?