Well, things like Lutris do the same automated configuring of the underlying tools to run Windows games under Linux and putting it all under a "press button to play" interface as Steam as well as letting you manage your collection.

Lutris (and I believe Heroic too) even integrated with game stores and will list your games there and download them directly from there to install them.

What they don't have is the store part - you can't actually BUY games from those tools.

People using for example Lutris to play GOG games in Linux, have pretty much the same experience as using Steam from a browser to buy the games and then Steam app to manage your games collection and launch the games.

Having both Steam and Lutris, I personally prefer the latter because it seamlessly integrates with multiple stores and even works fine with games from other sources (such as games I bought in physical format way back in the day or games I bought directly from the developer).

Sure, the open source apps doesn't include a store, but as I see it that's actually a good thing since I'm not interested in getting the sales push to buy more games everytime I want to play a game, same as I'm not interested in seeing ads when I'm browsing the web.