Tier lists are based on players of equal skill. If new tactics or strategies are developed with certain kits / classes that give them upper hands in the overall metagame against other classes, then they go up on the tier list respectively. However, having a better tactic with a kit =/= more general (overall) skill. It doesn't take much thought to come to this conclusion once you have experience in the game, which judging by your responses, you may not have much of. I'd recommend gaining more experience before discussing certain things that are more competitive oriented on the forums.