Some info from the r/cassettefuturism post:

Rotary Un-Smartphone by Justine Haupt (real product)

Disclaimer: I have no affiliation with this product.

Source Rotary Un-Smartphone

Via Buttons & Knobs — Justine Haupt’s Rotary Cell Phone which you can...

The Rotary Un-Smartphone is a followup to this personal project. It's a production-ready ground-up design with all new parts (yes, the rotary dial too) and many neat bells and whistles.

• Pocket-sized (11.0cm x 7.5cm x 3.0cm)
• Light-weight (163g [6oz])
• Full LTE connectivity. Obsolescence-proof for at least another decade.
• Access and call your personal contacts perhapsfaster 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 for caller-ID and dial entry, and back-side ePaper for contacts display
• 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