[hoten]

Steam can list/launch your non-Steam games, but it isn't open source. Listing non-steam games is also a manual process and there probably isn't any library art associated with the entry if it comes from Battle.net or whatever.

[dharmab]

Steam supports custom library art and there's a large community database of correctly-sized artwork covering many games: https://www.steamgriddb.com/

[nottorp]

GoG Galaxy can handle Steam games too...

Probably not the proprietary launchers for the top predators... Blizz, EA, Ubisoft...

[metalliqaz]

I have been using GOG Galaxy to try and track my entire collection but of course its connections to other gaming services are always broken.

I've heard that other tools like Playnite work better but I've not gotten enough motivation to try as yet.

I prefer Steam's well-integrated interface. It would be nice if it could scrape other launchers too.

[nottorp]

Tbh my problem is not with launchers, I can live with separate launchers, but with having a full list of games I already bought on my phone when i'm digging through the console bargain bins.

At the least I have two copies of Mass Effect Andromeda and two of Valkyria Chronicles because they were very cheap and I forgot I already got them :)

[metalliqaz]

Yes, same. When a deal pops up I have to check Steam, Epic, GoG, Humble, Itch, and so forth.

[lamarcke]

After my endeavours with various store APIs and trying to get all of them to fit with our constraints, i understand why GOG Galaxy is always broken

Most of their external APIs suck tbh. Steam and PSN were the best experience i had, and the PSN one is not even officially documented. Epic doesn't even let you use their user library endpoints if you are not a partner unfortunately...