This is the first I've heard of Termux and now I'm curious what you use it for. Like are you SSHing into other environments?

SSH, and also when you're on the road and want to write a simple Python script to process something, or do something with your sensor data logging. Termux has a Python API to access sensor data, it has numpy, it has requests, so you can do a lot.

You don't need Termux for that, there are native clients for Android, I use this one: https://play.google.com/store/apps/details?id=dev.msfjarvis....

There are native clients, but can you use git to sync the encrypted passwords with your other devices?

And that was just one example. You can also use python as a much better calculator, share files over wifi with a web server etc.

For me ssh to access my main Emacs session is a big part of it but I also run some shell scripts and CLI tools and services written in Go. ssh-ing back into the phone for file transfer is another important use.

Curious, is the Librem 5 an alternative you would consider?

Sure, it is a good alternative. But I still need a phone to do some work, like Whatsapp and banking apps (which I don't think Librem supports). So I am waiting for it to become stable and a little mature.

Makes sense!

Does LineageOS provide a workaround for this?

Unfortunately there is no good alternative to Termux (its Android API). But with a rooted phone you can use chroot to install a Linux distribution. LineageOS is just a popular ROM for rooted phones.

I run lineage but I don't typically use my terminal on my phone unless I'm using it for SSH. I hadn't though of the chroot angle though. That's rather interesting...

It was just a figure of speech and if you know how Termux works even a rooted phone is no alternative. (Termux exposes Android APIs, like camera and GPS.)