Completely agree. People lament the death of the RTS genre for all kinds of reasons but I think the biggest one was the early-2000s switch to 3D. Performance considerations meant you have way fewer units. The only exception was that Supreme Commander was somehow able to get around this, but suffered heavily from the second big problem with 3D RTSes: the tiny unit models are so much harder to tell apart in 3D compared to 2D.

The RTS switch to 3D was a mistake and I think RTSes will continue to fail until their developers realize what actually makes them fun is actively hindered by this technology.

I'm on the gameplay > graphics bandwagon too but StarCraft II and Age of Empires IV are proof that 3D is not the problem.