The last HN article with the Lilygo T-Display (ESP32-based) that showed the news articles was cool, and screwing around with that led to finding an open source weather program for the better T-Display S3. Stupid easy, cheap and fun to throw together or mod.
I am currently building an auto-updating webcomic display for a community bulletin board. It's of course a great application for an e-ink display because it only requires power to update.
Further implementation details: I'm using an ATTiny85 to feed 120 seconds of power-on time to a Raspberry Pi Zero W every 12 hours or so, via a MOSFET. That way I don't have to keep the RPi powered on. Power source is 3 D-cells.
you'd think they'd be useful for safety critical logging. You can guarantee some information on power loss like GPS coordinates, error states or situational Info like tidal information.
I always wanted to try overlaying physical controls for realtime readouts but use these displays for generated backgrounds like gauge scales. Or like a clock background that still had physical hands.
Though my next project will use the smaller 1.54 inch ones, very targeted ;)