Once you have a large enough fleet of roughly the same shape, it starts to make sense to build some automated cleaning thing. I'm picturing like, a long tube with vacuum ports in it that can just be shoved in by a robot arm to vacuum each seat. Unless there's a wet mess, that'll basically get it 90% of the way there.
I think we'll see such self-driving taxi interiors optimized for staying clean and then ease of cleaning. At the limit, think like a stainless steel kitchen that can just be sprayed down. Or these sort of self-cleaning public bathrooms: https://www.youtube.com/shorts/z81KtV9w5fo?feature=share
