GOG is pretty good because of this. I check in there if I’m considering buying something on Steam. There might still be compelling reasons to buy on Steam, like I bought Parkitect on Steam because a review on GOG specifically called out how the mods really only work well on Steam, but I’m at least checking first and maybe Wishlisting the game on GOG. I have fairly reasonable trust in Valve while Gabe is running it, but I feel like I can have longer trust in keeping copies of installers myself.