Watching Netflix I suppose. Sleeping (although I'm sure some get paid for that in the right circumstance) ... Even watching Netflix could be a slog if you're doing it for some purpose (e.g. to clue up on cultural references) and it's an exertion of effort.

Don't you agree that this limits a lot the perspective of what you do when you retire, if retiring means not working anymore?

Maybe we agree that it's all work, but there are types of work that even though they're frustrating, they are also rewarding in specific ways that is interesting for those that retire.

Retiring is just retiring from employment. I suppose I'm drawing a distinction between formal employment and all forms of work. Yardwork is a nice example enjoyed by retirees.