Manufacturer lock-in can be quite a problem. I'm not saying the ESP32 solves this fully, but you can mix and match as you like, and it's highly encouraged. I think with the ESP32 most build upon Free RTOS but I'm not aware of a strict requirement.
Of note, you can just pull in a lib to use Wi-Fi and BLE on an ESP32 (C-3 at least). I've done it. It doesn't imply any changes to your firmware architecture. That's the part that bothers me about Nordic's approach.
And this chip isn't a normal QSPI chip where you read the datasheet. You have to use NRF connect, and Zephyr.
So, this brings up the obvious question: What if I don't want my whole firmware to be Zephyr nRF-connect, just for a Wi-Fi chip?