Canonical supported versions were based on snaps-predating app framework (click packages). There were a couple of phones released with it out of the factory (bq aquarius 4.5 and meizu mx4) and a bq tablet, but rest of the supported phones use android kernels for hw enablement.

Ubutouch has forked the software when Canonical pulled out and even runs an app store, but I think the best hw you can get is Oneplus 6t and then mx4.

I used mx4 as my daily driver for years prior to switching to Android for the first time 3 years ago. While not the fastest phone, mx4 was usable (things I hated most were sharp edges and how it would register touches in my pocket, and then get locked for 10 mins because of wrong passcode).

To be honest, I quite prefer the Ubuntu Touch over Android (and Nokia Meego/Maemo is up there too, but Palm Pre WebOS takes the cake as the best basic phone UX I've experienced).

I think Mobian has the biggest potential to be the pure GNU/Linux system in your pocket, so I am hoping it'd get Unity included too.

First time I've heard of Mobian, looks really interesting. Will keep an eye on it