

It’s not like they have to create the compatibility layers from scratch; Valve did it for them.
I do just want to point out, Valve didn’t do that - Proton is mostly just pre-existing software that they packaged together into an officially supported feature. I love that they did it, and having it in the biggest PC game platform presumably did wonders for Linux gaming, but it was most certainly not made from scratch.
Ah, seems you’re partially correct - steam has a command for downloading a specific depot version. You need to know the specific ID to download, and notably games can use multiple depots to form the game files, but I thought you needed to use something like SteamCMD or DepotDownloader for that.
I’m still upholding the fact that it’s not a “proper” feature, while I appreciate having those kind of utilities put in the user’s control, this isn’t something most people could figure out themselves.