Termux [0] is an excellent "other" method of having access to A LOT of GNU/Linux and FOSS tools on any Android device. You can also chroot a full distribution on it and get access to all the packages available from that distribution.
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.
Supposedly a few docks are coming out that will support it, but they seem to be fairly bulky.
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.