Vim and Emacs support Android. Vim is also on iOS.

VIM: https://play.google.com/store/apps/details?id=net.momodalo.a...

https://itunes.apple.com/us/app/vim/id492668168?mt=8

Emacs: https://play.google.com/store/apps/details?id=com.zielm.emac...

Yes, but on iOS you still can't compile or run any of the programs you write.

> Solidworks, AutoCAD, etc. don't run on phones

"AutoCAD" is a brand that applies to a large number of different CAD-related programs, some of which are mobile apps.

> Photoshop/Lightroom/Illustrator don't run on phones

Both Adobe Photoshop and Adobe Photoshop Lightroom are in the Google Play Store for Android phones.

> SPICE, VHDL, Verilog don't run on phones

Well, I can find circuit design apps that support a subset of verilog, but this is basically right.

> Emacs/Vi don't run on phones

There are ports of both on the Android App Store, supporting phones.

> There are a host of actually-useful programs that are completely unsuitable for run on phone-computers, that do run well on laptop-computers and desktop-computers.

There may be applications that phones don't have the processing capacity for or that work best with certain I/O peripherals that phones aren't often used with, sure. But the array of classes apps that are completely unavailable for phones is smaller than you seem to think.

SPICE, VHDL and Verilog typically run on some 56 core machine in a server room. At least once you are working on a sufficiently complex design.