You are dismissing a lot of things.

Steams memory footprint is generally lower. The social aspect of it actually works and can be disabled to free up resources (first mover I'll admit). And the UI is dramatically less offensive than the other "game launcher/stores"

Steam gives me the option to launch into my library instead of the store which makes it feel dramatically less "blah".

In comparison, just to play diablo IV I had to click off two popups in the battle.net launcher of "buy this".

When you add shortcuts to games on your desktop it bypasses the steamui entirely and just launches the DAMN GAME. (it still does do an update/validly check with steam if you are connected to the internet tho).