There's also MPU in even simpler/cheaper MCUs. For instance, ARM Cortex M0+ sports an MPU, and this architecture is used in STM32C0 ($0.24 in bulk) and RP2040.
I have no idea how the landscape looks in general, though.
I have no idea how the landscape looks in general, though.
Virtually anything with a radio these days (the MSPs were holdouts but mostly those are Cortex-M these days as well)