The OP states:

"Smartcards and HSMs are essentially two “brands” for the same thing: a chip which guards access to the data stored within it, and will only allow that data to be accessed in certain ways or under certain conditions. HSMs are the “enterprise” label for such devices, whereas smartcards are essentially the same thing, only cheaper."

Yubikey(mentioned in the title) is a TOTP card that works with the HSM on the far end though. They serve different purposes. You load the tokens into the HSM device.

They aren't the same thing. What am I missing?