I challenge you to get poop on your finger, wash it off under the shower head, and then rub your eyeball directly with that finger. Your towel has poop residue on it.

I use a bidet daily and sometimes theres still some poopy left after a few long sprays, I use toilet paper to dry off and do a check and then if its clean Im good to go, otherwise I hit it with some more sprays and check again. a few sheets of toilet paper is a lot better than no bidet but Im still not convinced a bidet by itself is good enough. at least here in the states bidets are simple bolt on squirters not a separate thing that might do a better job

I would share a body towel, there is just no necessity to do so.

Sorry you have to hear it this way, but a butt towel requiring a wash in detergent and even more water than you just flushed is less eco-friendly than two squares of toilet paper.