I used to do that for a while, and it got annoying very quickly. It still requires grabbing my keychain when e.g. sitting on the couch or lying in bed, NFC doesn't always read (there's very little UX feedback on whether I'm holding it in the right place and there is possibly an application layer problem or I'm not even close), and most of all it doesn't work on my computer, where I need to plug it in to the USB-C port (much less seamless than tapping).

Now I only have the Yubikey as a backup authenticator for my most valuable accounts and use a software solution for most low-value things.