I have been looking at Linux on phones(Ubuntu touch) with the intention to use it both as smartphone as well as desktop replacement. It really fascinates me. But it looks like there is no hardware anymore that supports display out and USB dongles. Why are there no up to date phones that have convergence mode?
Posting from my PinePhone Pro (Mobian) - last I checked a couple months ago, it worked alright. I used the metal body hub they sell on the Pine64 website. There are a lot of issues that will probably prevent this phone from being ideal for your use case though. This phone has been both a hellish nightmare while also unquestionably being the coolest piece of tech I’ve ever used. Might get around to posting a review on c/Pine64 if I get the time.