>>45021431Pokemon did benefit from the Physical/Special split.
Crawdaunt and Absol for example, became leagues better by virtue of being able to use its higher attacking stat for its STAB.
They dropped in a tier list not because the split made it worse, but because the split benefitted other Pokemon more and the competition with those Pokemon and newly introduced ones only became tougher and tougher, especially with power creep.
>Improving isn't in a vacuumImproving is both in and out of a vacuum. Improving your skills makes you better at that skill whether or not you are compared to possible others. You can be better than your past self, yet simultaneously be worse and falling behind everyone else. It's not that hard to understand.