Many manual jobs wear away fingerprints. I renewed my ID card after renovating my home and the fingerprint reader could not read anything meaningful. They told me that sometimes the state accepts those messy fingerprints anyway and yes, the request got approved. There is some jumbled fingerprint on my record now.

I would much prefer to have a pin on the yubikey itself with little keys or something but since that isn’t an option, fingerprint it is.

You can set a yubikey to require a pin entered on the host.

It’s a shitty user experience though, as loads of websites turn into “username+password+yubikey+pin+key button press”

Yep... which is why we use the biometrics one. End users refused to use the app as it was a pain.