I don’t think 7.62x51 beats armor at 200+ yards either.
Yeah. Hot rounds with steel cores, sure. Standard loads with FMJ, nope. But Geneva conventions and such. It'd be a lot better than 5.56/7.62x39 at 200 yards; the Marines are trying to drop the short-barrel M4 because they find it to be effectively ineffective against armor at 150yds.
.30-06
My reasoning is if you're going to carry a big round, carry a big round. .300 winmag. .338 Lapua Magnum. The difference in weight from a .30-06 isn't meaningful compared to only having to hit them once, and being able to shoot straight through various objects.
Ukraine
Drones, and specifically the ability to manufacture them cheaply, will win the war. Artillery that can't move within 30 seconds of firing is just waiting to die. The 777 and all the old soviet towed artillery is disposable drone food now. Even the M109 is a bad investment compared to a pile of Lancets, frankly.
But, there's nothing new under the sun. Medium range drones are the new artillery and infantry tactics won't change significantly because of the change. Short range anti-personnel drones are a different story, but I don't think they significantly change the rifle choices.