I dont really need it but good launchers make things easier, especially on linux where sometimes a specific patch or version of something like proton is needed and i dont want to spend hours figuring it out by trial and error. 

Im not a fan of launchers being required though, thats just DRM. But projects like Heroic launcher and Lutris are incredibly nice to have. Steam is alright, its hard to hate on a company that has done as much for linux gaming as valve has.