I do agree T3 air is an issue and it needs to be delayed. Compare it to T3 Land, getting T3 land doesn't produce results as quickly as T3 air.
T2 land can still beat T3 land or stop it and ACU with OC just cancels out early T3 land most of the time. Plus it takes a looooong time for your T3 land to become useful.
T3 air can go from 0 to 100 grossly quick. 1 Strat bomber can wreck everything if opponent doesn't match with T3 air immediately. Literally the current teamgame meta is someone has to go T3 air or most of the time the game is lost due to 1 strat killing all T2 mexes it can find. This makes the game very stale.
Idk about the 20 guys that are +2k and have perfect games where T2 air is busted or something but anything below that rating (or at least in my 1.5k experience), T3 air is king. T3 navy and T3 land take normal progression to become relevant while T3 air pays off almost instantly and cancels out T2 and T1 air.
Even if nerfing T3 air makes T2 air more relevant, thats perfectly fine with me. I want to see more of t1-t2 air stage on teamgames than the classic just rush t3 air because making t2 air = lose