really?
I know of zero studios that are still doing any painting. they are all digital. sk, china, japan - no one uses paint filmed one cel at a time, or any of the old analog processes anymore. I'd be happy to be wrong, but I don't know of anyone that's still doing painted cels recorded on film.
Even Ghibli. https://www.dqindia.com/features/studio-ghibli-blending-tradition-and-technology-in-the-age-of-animation-8921913
"Ghibli's selective integration of technology, primarily digital ink-and-paint techniques facilitated by software like OpenToonz, stands in stark contrast to the unbridled embrace of AI in the recent Ghibli-style art phenomenon."