The key word in the post you're replying to is "normal". Non-technical people don't (in my experience) plan for this kind of thing, like at all.

The idea of multiple hardware keys, which have to be enrolled individually to every site, is just not an ordinary end-user friendly activity.

So passkeys may be great for technical users (who are happy doing that) or corporate users (where centralized IT systems can be put in place) but not for standard non-corp users (which realistically, is most people)