Ubisoft doesn't need NFTs to let people transfer their games to a new account, and they don't need to let people transfer their games just because they've given you a fancy commemorative memento of the time you gave them money in exchange for not owning a game.
It’s one of the many reasons games are digitally sold now: there’s no physical artifact the owner can sell to someone else.
Why would Ubisoft intentionally create a way for homes to be resold without them getting a cut?
Since mistakes or malice can always occur, the real issue is that it isn't easier to seek legal redress. Somewhat tangential to this issue, I still believe it's wrong for these services to use wording and marketing that suggest you "purchase" or "buy" the game, when in reality you have no such ownership claim to the game as you would a similar, analog purchase of physical media or objects. I don't think it's fair that these companies can get away with using misleading language and obscuring the truth in legalese in a 100 page TOS document.
The "buy" button on these digital games storefront should say something like "purchase limited license," or at least something a little closer to reality.
I don't think it should be possible to "purchase" an online-only game that requires access to the proprietary game servers in order to function. You're renting the game and don't actually own anything.