Artillery is terribly vulnerable to whomever has aerial supremacy. In Ukraine neither side can freely roam over the others rear areas, to massacre their artillery.
Imagine a single pass by a B1 with 100+ JDAMs, each fed near-real time coordinates by surveillance drones. Just one scenario.
No one can use their planes and helicopters. There's a lot of drones all over the place. Ukraine and Russia are "near" peers. Sort of like what you saw in WWI where Germany was fighting France and UK on the Western Front.
Great if you have uncontested air space. Air supremacy is the key to using bombers. SAM missiles and fighters are the problem.