Why not make a phone that you can connect to a monitor and use like a computer? Like PinePhone but actually make it usable, with good battery, processing speed, cellular working on all carriers etc.
I think the way it is now is kind of perfect. 16:9 Mobile device for personal and some work comms, social media, media. Work computer for work, easy to move around if need to work elsewhere. Home computer for personal work, play, connectivity. really integrated into home stack, can't move.