I don't really need portability, I just don't have a desk or a good place to put one, and I like to use a laptop on my lap on a comfy chair or occasionally in bed.
What do you really need as a controller? How about a bluetooth keyboard with a built-in trackpad or button mouse thingy? Apple items can "cast" to a compatible (wall-mounted?) TV, or you can use Amazon Fire Stick or Google ChromeCast to send video to your local screen...
I bought a Roku TV used, and it's got the AppleTV function built-in, and Roku keeps updating the remote control app for my iPhone so it's pretty decent.
Would be way cool if they figured out how to let me use the phone keyboard to type in search terms for youtube instead of having to navigate the letters and symbols with up-down left-right, but maybe by 2029 they will get that dialed in???
here is a handy shelf which saves desk space for a small computer - you could probably bolt it to an interior closet wall to make it disappear...
https://eshop.macsales.com/item/NewerTech/MINIS2MM10/