I think the title is misleading. This project is about installing KDE on a smartphone over Cyanogenmod (which is a modified build of Android).

I am totally against Google and its restrictions and tracking proprietary code in Android but this project looks more like an attempt to get user base to sell them some paid services later.

Do you really need KDE to make your phone "hackable"?

Google did a lot to polish Android code and released it under an open license. I doubt that project is able to invest a comparable amount of work.

Having the same interface on desktop and mobile devices is not going to work well.

UPD: their installer installs a firmware (like twrp) that makes your phone unprotected from reflashing and stealing your data or installing a backdoor if someone gets physical access to the phone. They do not warn about it.