

Same is true for games on Steam if the developer decides not to use Steam integration (some features like achievements are ok I think). For example Noita doesn’t need Steam running, you can just copy the folder to another machine AFAIK
also there are Steam emulators
Imagine having Fortnite money and all you can deliver is the EGS. Yeah free games are cool I guess but it’s like the laziest approach regarding actually engineering and developing a solution