Steam predates all those platforms by years. The only platforms that I can think of predating it are long dead and didn’t have the same concept of ownership (gamespy, gamestorm, AOL, heat.net, etc). Indeed, part of why those platforms struggle or failed is exactly steams early mover advantage.
Eight years before Origin.
Six years for Ubisoft’s.
Fifteen for Epic Games Store.
Ten years for itch.io.
Five years for GOG.
Seven years for humble bundle (though their early offerings were literally steam keys).
Eight years before Origin. Six years for Ubisoft’s. Fifteen for Epic Games Store. Ten years for itch.io. Five years for GOG. Seven years for humble bundle (though their early offerings were literally steam keys).