I doubt much will come out of that, but maybe I am just burned by Ubuntu Phone. Which BTW still exists as a community supported version.

Otherwise you can run regular Linux on Android via chroot. I did that to have a "pocket nextcloud server" which is quite nice especially if you often use your mobile to share internet with other devices.

Oh and there is also Plasma Mobile and MaruOS.

and SailfishOS :D (but not 100% free)

I know about KDE trying to do their own thing :
https://plasma-mobile.org/

I wish we had a Linux OS ROM that was deployable across all types of Android phones. I usually buy a $40 to $50 knock-off phone for me and the family. Right now we are all using Lineage OS without Gapps on Galaxy S4 knock-offs. So far so good.

Well.. not really. Not yet.

But if freedom and liberty is your goal then you can always try to find out if your device supports Replicant.

Have a looksy:
https://www.replicant.us/

I will try out Sailfish soon. I ordered a Sony Xperia X and then a few weeks and Jolla should release the new sailfish for it, including android support. https://blog.jolla.com/sailfishx/

I have never used Sailfish, its the based on the linux based Meego that Nokia made, and then when they finally had the first phone announced that they only would do windows phones from then on dooming it as a flop even if it had very positive reviews at that time.

My Jolla C is all I need. SailfishOS is a great project, less features than android but it's a good compromise. I really hope SailsfishX will be a success because we really need alternatives to Android and iOS.
FirefoxOS is a failure and Ubuntu gave up their project without mentioning Windows Phone.

For me, I've been using Linux mobile devices for many a year.

Earliest device was a Sharp Zaurus, UK version, and then the cool mini-laptop types only available from Japan.

Then I moved on to Nokia N900 running Maemo Linux, which gave you, the user, full root on the device.

After that Nokia released only in Europe, not UK, their wonderful N9 phone running MeeGo Linux. It competed incredibly well with the other top smartphones available when it was released. Unfortunately Microsoft took over Nokia company at that point, and they focussed on Windows Mobile phones and some Symbian ones and dropped MeeGo (wahhhhh, boo hoo).

But a Nokia splinter group departed from the company and produced the Jolla company, releasing the Jolla "Sailfish OS" Linux phone. Unfortunately Jolla have not managed to fire up the masses, and their mobile hasn't grabbed much market share. But, they did very well considering. I mean, look how "Microsoft" and "Blackberry" have done in the mobile device OS market.

Now that Nokia has re-taken back their main phone production company from Microsoft, they're concentrating on Android phones. They're pretty decent ones too. Who knows, maybe Nokia / Jolla will do something which grows successful in the future.

I've really grown to love my old Jolla. Too bad it seems to be on its last legs.

I was really happy about the Sailfish on Xperia X deal until I read about their pricing model with yearly, non-trivial license fees. I doubt their fanbase is big enough to support that sort of lunacy. Can I just please have a PuzzlePhone with Sailfish OS? Please?

I just switched from SailfishOS to Android 7. I like the swipe actions, multitasking, and active covers, and terminal apps better on sailfishOS, but the GUI apps, both bundled and in the store are generally better on android. All apps for Sailfishos are gratis because Jolla refuse to implement support for paid apps, some(most?) of them are also FOSS.

I think SailfishOS has potential if they are bought by a russian or chinese company, but I don't see them succeeding with current management, and I don't think they have any chance in mainstream western world markets.