GNOME Foundation partners with Purism to support its efforts to build the Librem 5 smartphone

It goes back further then that.

Meamo with Gnome, which was then hacked up to support QT and turned into the OS that shipped on the Nokia N9. And the dozens of different variations and OS projects that have been spawned from that failed effort.

As long as it can send and receive phone calls, do texting, play audio files, and have a map program then essentially all my smartphone needs will be met. I don't care what OS or desktop or toolkit it uses. Totally irrelevant.

I still suspect, however, to get the most out of the phone people are going to realize that they really need to install LineageOS on it or some other variation of AOSP. If people really want a open source phone then it seems the path of least resistance is to work on improving the alternatives to the APIs and basic set of applications usually provided by Gapps. Working on trying to transform KDE or Gnome into a phone OS is a huge amount of work compared to just helping on improving one of the already existing FLOSS versions of Android. Later on they can work on getting Android functional on a vanilla kernel.

We are talking about the difference between months of works versus years of work.