>>63926765
People who get hit by other means don't make it to hospitals in general. A paucity in available artillery, especially on the lower levels on the Ukrainian side, means the people who do get hit by it are the ones who never make it back home, i.e. meat wave mobiks and assault troops.
The people in the rear, who have a chance of receiving medical attention, are generally not going to be hit by artillery, because due to its poor availability, it would be a relative waste, trying to strike low value targets, often dug in, with unguided munitions that are needed against troop concentrations or high value targets.
Drones are cheap and plentiful, so the Ukrainians make do with what they have, creating a severe bias in the statistics.