The confirmation came from the Steam support staff earlier this month when Resetera forum user delete12345 asked Steam support if he can put his Steam library in...
If you cannot pass on your ownership rights to your purchased games to your children, then you cannot pass on your copyright either, I guess?
Gifting is not the same as transferring an already bought game to another account. Can you do that?
It the same mechanism. They can do it, they just don’t want to.