@drmaddkap Short answer: capitalism

Long answer: it takes a non-trivial amount of work to ensure scaling can be done gracefully without breaking an app.

Yes, they could just have some generic scaled view like iPads did w/ iPhone apps, but that is a terrible experience compared to the competition (like selling a car without AC but with windows that'll never break).

And ultimately, manufacturers are out to make more money, not cut into potential profit margins for the sake of utility.

@drmaddkap isn’t that just Samsung DEX?

https://www.samsung.com/us/apps/dex/

@drmaddkap I’d guess it’s partly because bigger touchscreens are so much more expensive than CPUs that it doesn’t make much sense to sell screens that don’t have CPUs - especially when you need a CPU to decide the image anyway. (Same reason all TVs are now “smart”.) Making it a standard feature to use anything with a screen as a UI device (also like TVs) would be great, but capitalism abhors a standard

… could CarPlay/AndroidAuto be (ab)used for this?

@drmaddkap

Asus used to make an interesting 3-in-1 that fit into the marketplace there (unfortunately never released in the US). It was basically a zen phone that you could slide into a dock in the back of a tablet for a bigger screen and more battery. Then you could snap that tablet into a keyboard dock with even more battery.

It's just a shame the phone was only around midrange. I could imagine something like that being appealing for gaming on the go.

@drmaddkap

Incidentally, I'd recommend against the Asus ZenScreen Touch line. In an effort to keep them very light for portability, they are quite flimsy and don't have great battery life. Adding a half inch of battery and a wifi connection would make it the perfect device for what you wanted.

Maybe somebody else makes a similar device? That or you could duct tape it to a hardback book.