>>7247196No, they don't.
Only certain materials degrade quicker, like natural rubber and foams, but most are dependant on various factors.
Probably the reason why people seem to break their McFarlane figures is just because the paint settles over time and with heat, it will expand and stick. So when they move a joint, they break it. Most toys with hard plastics don't have the paint jobs that McFarlane toys do, so there's usually no issue with the paint being affected by heat/dust.
Besides, if it was the plastic rotting, the surface would show visible signs. The joints aren't as exposed to light, air, and even heat like the surface will.
So there would be cracking, leeching, blooming, etc noticeably all over the figure before a joint would start to rot.
see pic in how a joint would get protected simply by being inside and not on the surface.
