They are excellent in the hobby world. It’s generally when you need to do a bit of quick logic, an ESP32 can be dropped in to do it. E.g. change the colour of an led depending on a sensor.

They also form the core of a lot of IoT devices. Simple sensors and relays that can connect to WiFi and throw up a simple web interface. ESPhome, tasmota and WLED exist to make this extremely easy.

They are basically the hobbiest electronic multi tool. Powerful enough to do most jobs without bothering with code optimisation. Cheap enough to throw in and leave there.

While I use it on WiFi, I’m fairly sure my brother laser printer has a USB connector.

The key is that it should remain fully functional, even when lobotomised.

Kill WiFi, alongside ZigBee and Z-Wave coordinators and all core functionality should remain.