I used to have various Linux setups on my Android phones. I experimented with different chroot setups and applications, settled on just generating my own chroot using debootstrap and mounting it with a script in the Terminal app. XServer XSDL for GUI. It worked, but it wasn’t amazing.
These days I switched to proper Linux phone. Typing this on my PinePhonePro keyboard using postmarketOS. If you really want the best pocketable Linux experience you can get, this is by far the best. Might not be the best if you depend on Android apps, but my Android use case was mostly just browser and a few unimportant apps that have Linux alternatives.