I mean isnt steam a third party too? I agree that having to use two third -party applications to play a game is too much. Just try to remember Steam used to be hated too until they became indispensable.
It's fine if I buy it though steam, but if I buy a game on steam, I'll be pissed if another launcher pops up. For no bullshit at all, GOG is better because it's DRM free.
I just want an .exe I can throw into whatever folder I want, that launches the game and doesn't open a launcher or storefront(steam included). I don't care about all the useless achievements and progress bullshit, not to mention tracking data. I buy on GOG when possible, but not every game is on there.