Maybe you kid, but... I've been using a physical calendar on the wall this year. I also replaced my Apple Watch with a Casio F-91W some time ago.
You know what's really great? My calendar or watch never gets hacked and it's never unavailable because some overnight software update broke it! Sure, the F-91W technically runs software, but it has no connectivity. That's the important part.
Now if I could just figure out what to do with my phone... I don't think dumb phones are particularly secure, so maybe it makes sense to keep using Android? Or eventually switch to Linux on my phone?