And you don’t need the official Steam client to download games. There’s tek-steamclient and steamctl, for example.

I don’t get what that has to do with DRM. For example, I need to have a package manager installed to install packages. Doesn’t mean the package manager is DRM.

How is that any more DRM than GOG requiring you to use their website to download games from them?

How? Steam games don’t necessarily have DRM, they can be the exact same files you download elsewhere. And the Steam client may be proprietary, but no mechanism prevents you from copying it around or using it, other than requiring login data, which stores like GOG also require?

It’s not about “someone else probably will”, it’s about “someone else already has”. No one is advocating for diffusion of responsibility.