>>64146006 (OP)
Artillery hunger is a major problem for both Russia and Ukraine, but Russia uses their air force to supplement the dwindling ground fires. During the Ukrainian offensive against the Surovikin line they used helicopters with ATGMs hovering 10 km behind the front line to strike Ukrainian armor that revealed itself during assaults, right now they mostly use glide bombs to level towns and villages that Ukrainians use as strongpoints along the front. (Though as far as I know these strikes are mostly concentrated around Pokrovsk and Sumy). Losing the air force would completely cripple the Russian ability to advance even at the current snail's pace
Ukraine uses its air force primarily to supplement their air defense, hunting Shasneeds and other such slow moving drones.
Ukraine losing its air force would mean that more of those would make it through, but not much would change on the frontlines.