I think Steam and GOG are examples of well curated (specialized) app stores. I searched a bit and it seems there have only ever been a small handful of reports of Steam accidentally allowing malware to be distributed with a game ("Abstractism" is the only one I found, that had apparently had a crypto miner embedded).

To be fair, Steam also was collecting 30% fees (I believe they have reduced recently, mostly because of pressure from Epic), so from this point of view it's not better than Apple.