I think the parent just tried to demonstrate what the "arm race" really mean. I.e. they just countered your hypothetical with another one.

As for the the Russians, they clearly shown that spending tons of munitions to make holes in the open fields is not really efficient. [1] Ukrainians on the other hand are pretty successful in counter-battery fire using US (sic!) systems. See HIMARS, for instance.

[1] https://s2.reutersmedia.net/resources/r/?m=02&d=20220617&t=2...