In general the Steam Deck is not the kind of device that is going to run things at max settings. You are gonna play at 720p30FPS low settings but be happy you can play at all on a train or airplane. It’s really meant to be a competitor to the Nintendo Switch than a replacement for a gaming PC.
You can stream from your PC to your couch or bed if you are at home.
I got a monitor stand to put my monitor such that the middle of the screen was level with my eyes. Made my neck hurt worse. It needs to be a bit below eye level.