So what happens to war fighting when tanks finally have to be mothballed, when air power, after so many decades of trying and failing to do so, knocks them off the board?

Your concerns about drone swarms as antipersonnel (even anti-civilian) weapons are absolutely worth worrying about, but however that issue gets handled, I don't think it's realistic to expect that drones are going to disappear from the battlefield or that tanks are going to retain their role as the primary force projector for ground forces.

So what next? Trench warfare again? It was the tank, after all, that broke through that paradigm and allowed armies to become highly mobile again in the face of machine-gun fire and other accurate, long-range antipersonnel measures.

If "boots on the ground" can't shelter behind tanks and inside APCs to get from point A to point B, then all our doctrines and tactics have to be re-examined. It's not clear to me where that would lead.

Have you done any thinking about that?