That is odd, I regularly use my Yubikey on multiple devices, that was the biggest draw.

The Yubikey is the "one device". But most people don't buy Yubikeys so the "one device" is, in practice, a smartphone.

	▲	Telaneo 2 days ago \| parent [-]
		Even then, unless you use one for work, where work can issue you a new one if you lose it, you're going to need (at least) two Yubikeys if you want to go that route, because not having a backup is a bad idea.