As far as I can tell, it's just de-googled android... It is going to have the same eventual problems as any LineageOS, e/OS/, or GrapheneOS phone will have.

Unfortunately we need to come to terms with the fact that 1) Android is not Linux after all of the bastardizations Google has done to it and the control they maintain. 2) We need hardware mfrs on board for fully Open Source drivers for mobile hardware.

Basically all of the Linux phone options I've looked at have been disappointing. You've got people making open source OS like Sailfish or PostmarketOS or UbuntuTouch, but they only work for pretty narrow (and old) hardware and they don't get 100% functionality on basically any of the hardware. FuriLabs was the first one I'd seen claiming you could use all of the features of the hardware, but even then it is using a bunch of (basically) compatibility layers to trick android apps into running, so I don't even know if that will work after Google gets done with their plans.