Of course they have, literally billions of times. Digital assets are represented by the intellectual property license you buy because as we know digital assets

Of course they have, literally billions of times. Digital assets are represented by the intellectual property license you buy because as we know digital assets (and really most things trivially copyable) are not themselves scarce. This is true of NFTs as well, some of which grant no rights what-so-ever and some that do actually grant a license. That license grants you rights to use the asset in a set of circumstances. For example you can hire freelance artists to make models for a videogame and get full rights to the IP. Buying an e-book or music works the same way with less and different rights granted. You can commission an artist right now to build you a VR Chat avatar, a Second Life avatar, a sweet PFP for Twitter and your own set of emoji's to use on Twitch etc. and get full rights to the images created. No NFTs needed. If you want to take your VR Chat avatar into Second Life well that's going to need some kind of standardization not NFTs.