You're not wrong but those aren't insurmountable. Of course the Steam Box is a better experience, but I built a remote starter for my PC and a dumb little Go program to switch the displays and disable some devices.
End result is I tap maybe two shortcuts on my phone and the computer is on and switched to the TV.
Do you have a script which bypasses login screen and switches input on TV too? I don't think so. Anyways my problem is that it takes a programmer to solve this even partially.