The first ESP32 board I worked with had some damn WiFi stack running in the background—not nearly as "bare metal" as I had come to expect from having just stepped out of the Arduino world.

(I've since learned, from an LLM, ha ha, how to turn that off if you don't need it.)

Well esp is wifi baked in the chip. If you want determenstic clock cycles then go for stm32. If you want easy quick setups. Like an interface for a fatbikes, washmachine, dashboard for a car, then go for esp