For me personally the limiting factor is the keyboard. If it's a PITA to write something, I'm not encouraged to write productive things on a smartphone.
I've got a foldable Bluetooth keyboard and my phone supports Miracast, and for brief moments at a time I can pretend I have a weirdly small laptop.
It's a "present"/"past-future" that Microsoft envisioned years back that we have all the technical solutions, just not all the practical solutions. Android is too fragmented to sell such a vision wholesale across the platform, and Apple too disinterested, too invested/stuck in keeping devices to specific niches (because it sells more devices).
I just got a Blackberry KeyOne, with a physical keyboard. It is no longer a PITA to write short text messages or emails of a few sentences. I still wouldn't write anything substantial with it.
It's a "present"/"past-future" that Microsoft envisioned years back that we have all the technical solutions, just not all the practical solutions. Android is too fragmented to sell such a vision wholesale across the platform, and Apple too disinterested, too invested/stuck in keeping devices to specific niches (because it sells more devices).