Windows simply needs a good console mode and we're there. Pre built market needs to mature the fuck up or steam console needs to be a thing again and we can be there now.
It genuinely needs to be even more streamlined.
As silly as that sounds, anything will be used as a discouragement, regardless if xbox/ps requires initial setup too.
I recently plugged my PC up to my TV so I could game on the couch. It works well, but I had some kinks to iron out. Big Picture Mode can play a bit of hell with multiple monitors, and I've sat down on the couch with a controller just to realize Steam wasn't the app in focus and had to go back to work the mouse enough times that I've got a wireless keyboard with trackpad on order. I also wrote a Powershell script to switch audio and display settings and bound it to a keyboard macro on my G910.
I'm happy with it now, but Steam Big Picture Mode is not quite plug 'n' play yet.
Ah yes, you're indeed correct - multiple monitors can cause some weird behavior still. One tip though, you can go into the settings and choose which monitor Steam Big Picture will use as the primary one. If you do that, it will automatically change this setting on Windows whenever it's running so that fullscreen games boot up into the correct screen, and you have less issues with losing mouse focus.