Also, "infantry" has varying levels of performance. For example, it's safe to say that 10,000 bullets every 6 years of training, but especially on the first year of training, where units can pass a test where they hit 50 targets at ranges 50 to 400 meters, in 160 seconds. With 10 of those targets moving left at speeds varying from 4 to 10 km/h horizontally. Also, they need to be able to have actual equipment, like knee pads, and armor that can stop a .308, and tourniquets, elastic bandages, and packing bandages, and vitaminized blood transfusion devices on every 20 units. Also, for every infantry unit that has color night vision and thermal vision quad tube goggles, they are statistically worth 300 infantry that do not have such equipment. TRAINING and GEAR is worth MORE than simple blood and protein shakes.
Also, it's not just about artillery, but the amount of artillery shells that can be used.
In war, jets, cruise missiles, and long range artillery have a much more pronounced effect. Infantry can be leverage those aspects to be more effective, but without those elements, they are far less important.