I still think there's room for a device like this in real practical use.
Not for it's original application, no way would I want to give up modern software, but in embedded controls, something that gives you the full power of being able to do "Apps", while being cheap and small enough to have real dedicated devices.
Devices like this could be made insanely cheaply now, seeing as how $3 ESP32 type chips have more power. And the battery life would likely be measured in years today, since we wouldn't be using them to replace phones, we'd be using them to control our sprinklers and smart home devices, as calculators, etc.
We reached the good enough point for these so incredibly long ago, and the applications are so simple, plus there's no need for them to ever be directly exposed to the internet except on private WiFi.... they probably wouldn't need updates, at least not of the type an app would notice (They might need Bluetooth protocol updates).
It could also pair with a real phone and serve as a single-function interface device, a physical "app" for making phone calls, checking the weather, playing GB emulator games, etc.
At this point, anything that has a display and microcontroller could jump to PDA level capability for a few bucks more, and all these "Smart devices" would never go obsolete due to cloud crap again, you'd just install a new app.
Right now I think M5Stack is the closest thing, but it's not that popular outside of DIY, and there's no ecosystem around it.