It seems like a particularly stupid design choice to make a launcher for Linux and yet refuse to do something that both simple and required for most Windows game to work in Linux which is launching them with Wine AND DXVK, same as Lutris and Heroic do.

You're basically just insisting that they could be purposefully incompetent.

Sure, technically, they could, but then what would be the point of spending money on a GOG Galaxy Linux version given that only a small fraction of the games in their store have a native Linux version?