I think it also has integrations for some other things too, so you can use it to launch all your games from various launchers instead of remembering which games are on which launchers and opening each one to search for the game you want to play. It centralized your games into one spot which can be nice.

Its a bit better than that, its a bit closer to an all in one launcher /downloader client for all your games from (steam)/gog/epic/etc

Like the other comment says, it's closer to Heroic Launcher. It is owned by GoG, but it also interfaces with other stores. Valve will/would never do this.