My point is that GW never had these extremely difficult teams to face. Especially on four of the nodes. Not trolling. GW has definitely changed and not for the better imo.
GW has always had extremely difficult teams. But the matchmaking is based on the power level of your top 5 toons. So if you are suddenly seeing multi zeta squads at the end of GW with no hope of beating them, it means the top of your roster has gotten strong enough to draw those squads in matchmaking, but you've not balanced the rest of your roster to compensate. As an earlier comment pointed out, you've most likely fell victim to overspecialization and it's gonna require some effort to fix it. The same thing happened to me about a month or so ago and I just got back to a point where I can consistently beat GW again.