Yes - the idea is that it takes quite a bit of work to create a Meshtastic node on an ESP32 with Arduino. If you just want a basic node that can do things - think about a sensor reading temperature, humidity, etc., maybe accepting incoming traffic for configuration and actuation - it takes a while to do it on an Arduino. With this, you can get up and running in an afternoon.

BTW, looking at the code, I don't think it would take much to bring it over to a different architecture. There are just a few "#if defined(ARDUINO_ARCH_ESP32)" and they seem to be used for RNG and little more. It uses Expressif's mbedtls, but you can use the vendored copy instead (at the monent the vendored version is just used for unit testing). So I suspect that any board supported by arduino-lora should work more or less out of the box.