Basic functionality like satnav, e-mail, word processing, are all essential functions. Their attempt to create "just a phone" fails bc smartphones, despite the name, have never been "just phones". The modern phone is a general purpose computer, a camera, a navigation system, a means of sending audio, text, and imagines, and a media playback device at minimum. Their attempt to create a "pure" phone by stripping out core functionality smacks of nostalgia more than a practical attempt to make phones less harmful and invasive. they would have done better implementing hardware and software that allowed the user to block advertising, take fine tuned control of notifications, and overall have more ownership and control of the machine, rather than trying to strip the machine down until it was a gimmick that would necessarily need to be supplemented by another, full featured phone in order for the individual to function in society.
Minimalism is a scam and someone who claims to give you power over yourself by giving you less agency and control probably won't deliver on their claim. We cannot go back. We cannot return to a simpler time that never existed. We must pursue mastery. Attain heaven through violence.