Most games (I own on) steam can launch just fine without using steam. In fact I do that all the time. Come to think of it, I've never launched a game I bought on steam through steam except maybe the first time and then I "pin to taskbar" and launch through there.
Using steam for sales and activation is quite rational. Do you think we should go back to CD keys or other preshared secrets written on paper?
I've had to repurchase many games over lost/stolen activation codes. I don't really want to go back to that place. It's like cryptocurrency - sure you have total control but you better never fuck it up even one time or it becomes worthless.
It's definitely terrible that half of mobile users can't run code without the permission of their platform and the other half could eventually lose the ability to do so.
But the stakes are lower because the phone is a time-wasting/consuming device and not a general purpose/productivity device like a desktop.
For DRM free games you can just run the executable directly without steam even being open. Maybe we should prosecute the publishers who don't check the box that allows that?