>>7868544With IF's case, it's not because of the plastics, it's due to the engineering. Hasbro/Takara are generally more durable because they have to adhere to toy-safety standards for toys that marketed for 3+, 8+ ages. 3Ps don't need to follow the same standards obviously.
And even for Hasbro/Takara, their 15+ "adult toys" have far more relaxed standards, which is why you see more breaky-snappy issues with their MPs.