alt Hacker NewsThe benefit of running Linux on a what used to be an MCU is that you're getting the best network stack, Bluetooth/Wi-Fi stack, one of the best device drivers (say for USB Host), stock and very well tested software, etc.
For your use case, you need raw performance and low-level control, and you have it. But for IoT device which is all about network more or less, there's usually no need to go low-level.
ESP32 for Wi-Fi handling uses wpa_supplicant port from Linux for example.
You can run a real, multi-user Linux with as low RAM as 8 MB. You get the benefit of running any Linux-supported programming languages (and combine any amount of them without extra effort, just on a real machine), established portable abstractions, established memory protection model, ease of debugging.
You can run both though. Both FreeRTOS and Linux simultaneously, where Linux is a FreeRTOS task on a dedicated core. That's how several Linux ports work, haven't checked if Espressif's works this way as well.
Nobody is going to build an IoT device with this MCU running Linux. It's only able to access 64 MB of RAM from its slow cores. There's also limited support for 32-bit RISC-V in distros so anyone looking to run Linux on this will need to build everything themselves. Easier to just get a cheap ARM SoC that can probably run Android.
Or you could just use it as a microcontroller. Networking support is already good. Programming language support is better than you think (C++, Rust, Python, JavaScript). Debugging just works on newer boards.