No moral overtones intended, the point being that the low cost and the form factor significantly lowers the barrier to entry.
I've been using a GPG smart card for a long time, and it required a separate card reader, and both card and reader were easy to break. A YubiKey 4 fits on a keychain, is hard to break (though some of my colleagues succeeded) and you just plug it in.
I like my smartcards. Bummed they didn't catch on. How do you feel about losing the PIN and using a password? I like how, if I'm at my desk using a hardware PIN pad, it's much less likely i'll have problems.
I've been using a GPG smart card for a long time, and it required a separate card reader, and both card and reader were easy to break. A YubiKey 4 fits on a keychain, is hard to break (though some of my colleagues succeeded) and you just plug it in.