I might be wrong, but I believe a fingerprint is equivalent to around 80 bits of entropy which is roughly the strength of a good 13 character password.

A determined adversary can do things like lift a fingerprint from elsewhere and use that, but it's not really something I worry about too much. They could also arrest me and press my finger down on the sensor or beat me and I'll tell them every password I can.

I mostly worry about having strong credentials to remote systems.