Artillery is only viable on Ukraine's side because Russia is too incompetent to manufacture long-range (30-50km) FPV strike drones at scale. Currently only Ukraine has pushed the "kill zone" to the 15-25km mark. Russia is behind. But this situation will not last, drone technology will improve on all sides, China will innovate on drone range and Russia will buy those drones. The drone "kill zone" will surpass the range of artillery for all sides.

This is happening in a few years.