Raspberry PI PICO could be a great controller for servo control. With the hardware PIO, the PICO can control the servos by hardware, without usage of times/ interrupts, and limit usage of MCU.
Drive the 6 servos on this robotic arm to take very little capacity of MCU, so the MCU can deal with other tasks easily. Detailed usage/explanation of RP2020 PIO programming as attached. This 6 DOF robotic arm could be a good tool for program teaching/learning, of robotic and Pico usage. There are 5 MG996(4 needed in the assembly and 1 for backup) and 3 25KG servos (2 needed in the assembly and 1 for backup). Note that for the servos the angle arranges 0°~180° all the servo need to be preset to 90 degrees (with logic HIGH 1.5ms duty ) before the assembly to avoid servo damage in the movement.
This product includes all the necessary items needed to create a robotic Arm, based on PICO and Micropython, for a learner, it may take 2~3 days, including the ARM assembly and basic programming, with Makerfabs given guides.