You can preoder a kit to make your own rotary cellphone

Official site:

Pocket-sized

Full LTE connectivity. Obsolescence-proof for at least another decade.

Access and call your personal contacts faster than with a smartphone

Use your own SIM card with your favorite carrier's "Bring Your Own Device" option

Real (mechanical) ringer bell made gold or silver-coated brass; externally visible

Receive basic SMS messages and send pre-typed messages and numeric strings

2 displays: Front-side OLED and back-side ePaper

Physical disconnect switch for the microphone

Mechanical power switch

MicroSD card stores contacts list as a text file

TRRS headset jack

USB-C charging port

Incandescent-like indicator LEDs

Weighs 163g [6oz]

Injection molded parts available in several striking colors

Hackaday has a brief article about the ongoing project.