For true high-volume, cost-driven products, **8-bit microcontrollers** still make sense. PIC16/PIC18 are boring but rock-solid: long lifespan, steady cost, easy factory programming, and they endure nasty power/ESD better than a lot of inexpensive 32-bit chips.
STM8 could’ve been the bridge from STM32, but ST never really committed long-term. 32-bit is beneficial when firmware churn or reuse concerns, but if the code is simple and frozen, 8-bit usually wins on BOM risk and lifecycle, not core width.