#1 you’re also restricted to whatever plays nice with the steam input system, and custom inputs are generally more tedious to use than a mouse and keyboard.
#2 that’s the entire point of the Steam Deck.
#3 isn’t the hallmarks of something “powerful”, I’m surprised that you would consider 30 fps acceptable given that you know what 240 fps is like.
#4 it’s not cheap. It’s just at the right proce for the hardware. The only reason why it doesn’t feel worse is because it’s running at 1280x800p. The display is literally from the discard pile with its terrible colours.
#5 Windows could do the same if Valve tried hard enough. Suspend/Resume isn’t that special and I’ve manually invoked it on desktop for all kinds of things before. >Task Manager.
#6 that’s because Steam is doing the legwork to make things work for you. See what they did with Elden Ring’s stuttering problem. I challenge you otherwise to access the game directories of any game running through proton. There’s a whole emulated filestructure that you have to understand before modding the game on Steam Deck.
Power user stuff is outside the scope of gaming for most people.