With a physical good you’re transferring ownership of that “thing”,
A use-right is also a thing that can be sold and for which stuff like the first sale doctrine applies. Possession and property of the use right is all yours, even if it does not include the right to make additional copies, that is, to sublicense.
At least that’s how it works over here, always has. You can get perfectly valid Windows Pro keys here on the cheap, there’s a small cottage industry buying up volume licenses at bankruptcy proceedings and the like and unbundling them. If Microsoft can’t stop that then Valve won’t, either.