This is only half of my password; the first part is a password I can remember easily with numbers and letters, the second is the generated key.
This means that even I don't really know my password and if someone found my Yubikey then it's useless to them without the other half that only I know.
(I do have a printout in a safe place of the key and also a backup Yubikey)
I use this password for my computer as well as my 1password vault which is generally filled with randomly generated keys for each website.
Might sound a bit overkill but if you can; why not?