I love the idea of hardware keys, and would absolutely use them for the essential stuff (email, domain registrar, bank) but they're just too expensive, while plain old TOTP 2FA is free and provides 99% of the benefits for my use case. TOTP also has a much better workflow in my experience, but this isn't that big of a problem for the things I'd consider essential, but it would be annoying if I were to use a hardware key for everything.

I can buy 6-8 physical keys for the front door of my house for the cost of one Yubikey. Even though there are options at half price, that then gets eaten into by the need to have two or three of them, since a backup is not optional for this sort of use case. I can't imagine convincing one's parents to buy 'a key for your email account' will be easy when the old way mostly 'worked fine' and was free, meanwhile the new one will cost them a non-trivial amount of money. It's an easy flow if you're their sysadmin, but I wouldn't want to throw my parents into the deep end of hardware keys and have to explain to them that they don't need the expensive one, but still have them be discouraged by the mere existence of 100+ dollar options for what should be damn-near throwaway hardware.

Passkeys somehow manages to have a worse workflow than both though.