Its also based on wine, they can’t fork wine and close source it. But you can fork it and use it anywhere else, just have to make sure any changes you make are also open.

So Lutris is free to use wine/proton.

Sometimes, and it isn’t as transparent as GOG.

Proton is open source, you don’t need to use steam to benefit from it.

Care to elaborate?

At least you know they can never enshitify what you have already bought and downloaded.

Valve don’t even care if your game has PC and console players playing together.

We have GOG too