I'm sure there are some extra security features in here, but I've been doing this with my mobile phone for years.  I think having another dedicated device to carry around isn't what most people want.  We already carry our phones everywhere we go and using that to login to our computers and unlock doors is probably the direction most would like to go.  Also, with things like WebAuthn on the horizon, I don't see many people willing to adopt this when more cost effective options are right around the corner.