Get a Steam Deck. Looks like Flightgear will run on them and you can use them as a portable PC when using it with a docking station.
I’m not saying this is the best choice but I went from a gaming PC to a laptop/Steam Deck and haven’t touched the PC since. Best of luck with whatever you decide.
Ah my bad. I’ll put my hands up and admit I gave a very cursory glance on Google before leaving my comment.