Termux is cool tech (including running full Linux in a chroot). I would also mention UserLAnd [0] to run full Linux distributions sand specific application with a simple install.

The thing I am missing the most is HDMI video out, as my retired Nexus 5 could do with MHL and a simple dongle on the USB micro port. That dongle could also provide power and another USB port for a mouse or keyboard. Very few modern phones seem to have any video out other than casting. I do see that DisplayLink does support Android, but I've yet to find a dongle that also provides USB C power delivery in a nice portable package.

0. https://userland.tech/

> The thing I am missing the most is HDMI video out, as my retired Nexus 5 could do with MHL and a simple dongle on the USB micro port. That dongle could also provide power and another USB port for a mouse or keyboard. Very few modern phones seem to have any video out other than casting. I do see that DisplayLink does support Android, but I've yet to find a dongle that also provides USB C power delivery in a nice portable package.

Many phones support USB-C's DisplayPort Alternate Mode which basically does HDMI over USB-C and allows for power and data, a cheap adapter [0] is all you need.

[0] https://www.amazon.com/dp/B07R7PD8TR

I'm using a USB-A DisplayLink adapter with a USB-C OTG adapter on my device, works very well for traveling, but yeah definitely wish there was one that was just straight USB-C and had a power pass-through.

Supposedly a few docks are coming out that will support it, but they seem to be fairly bulky.