To answer it please don’t be bothered by the mass-produced low quality AI videos which ran rampant and now are being cracked down by YouTube aggressively.
Mork Episode 1, however, is a good one, made fully by generative AI and can be used as the standard of AI movies. See the link.
Link: https://youtu.be/F6MgT_Bdgz8?si=SqLKmTLRjoxjfJ2X