It's very competitive for applications that can make good use of the programmable IO feature. Other chips with similar capabilities are substantially more expensive.

It's also clearly going to have a great developer community building up around it, which has great value in itself.

It's also great value as a "easy to integrate cheap module" which is what they initially pitched it as.

Of course these days many applications need a wireless interface (wifi/BLE) and you can get competitive parts at similar prices to the RP2040 (ESP32 or a BLE MCU).