So everything from 2000 counts?
2000 is basically when modern action figures started.
McFarlane was already experimenting with super articulated figures in 99 or 98. They were already doing double joints, ball-hinged hips/shoulders, ankle rockers, etc, BUT it was crazy random. So one arm had just a ball-hinged shoulder, but the other had a swivel.
Toy Biz was a copying McFarlane too, along with the rest of the industry. So scale in the early 90s went from 5" to 6" by the 2000. By 2000, Toy Biz was being more even with articulation, as engineering was mirrored for across the body. So both shoulders got ball-hinges, both hips were ball joints, both knees were double jointed, etc.
See pic being a perfect example of McFarlane using the same engineering/sculpting they were doing in 1999 but in 2001.
In short, western action figures wouldn't be affected much. Maybe we wouldn't see hinged inner shoulders and that's about it.
Eastern figures would still be stuck in the 80s.
>>11182802McFarlane made the Armitage, Akira, Trigun, and, Tenchi Muyo figures in 2000.