What is the problem with actuator wear and impact tolerance? — answered by Engineer Saeed Baatiah
The high-precision joints and actuators needed for smooth motion are the same parts most fragile under impact. Real play means high-speed collisions and repeated falls from full height, which wears actuators and knocks joints out of calibration. This is an explicit engineering trade-off — precision against ruggedness — and combining both at reasonable cost is what remains unsolved.