like a great standup routine you can rewatch 5 times but an average isekai only once, maybe its a density of the content thing

Weird. I have roughly the opposite stance. things that are 6-7 / 10s for me are much more rewatchable than 9-10's. I always enjoy the shows I like more, but i feel like if i watch them too often they don't hit, I need enough time (a year min) between rewatches to forget most of the details of the story, but with a slightly good show it's like I never get super invested, but I can rewatch it a few months later and have roughly the same slightly enjoyable time.
of course truely mid or worse anime I will only watch once, or drop.

I used to rewatch tv so much it was kinda comforting