In regard to the linux comment you might want to try Heroic Launcher. Open source launcher that is lightweight and combines Epic, Gog and Amazon with Wine/Proton integration.
I'm actually really, really hoping that third party launchers become a thing as if these stores have any common sense they'll realise that agreeing to a standard and letting users access their libraries via a single app is the only hope in hell they have of competing with Steam.
What I would like to see (which will probably happen around the same time I am gifted a unicorn) is to have a unified, standardized, non-publisher-controlled, non-profit game system. Where all publishers are allowed to put their games, with a central API for things like license activation, friends systems, etc. It could have a store component, but also just allow activation of keys from wherever. So Ubisoft could be like "nope, everyone has to buy keys from us so we don't have to share our cut with retail", but the game would activate on the central system, downloads would be managed by the central system, etc. The publishers would all have to contribute to running the system and feature improvements, and it could also be funded by proceeds from in-system game sales.
