I should have pointed out, the big difference between the rival weapons is political. Ukraine is restricted to using its JDAMs against targets in occupied land. Russia isn't bound that way, which is a problem for cities close to the Russian border, such as Kharkiv and Sumy.
They don’t have them same range.
https://en.m.wikipedia.org/wiki/Joint_Direct_Attack_Munition
The article does say there are longer range versions
“hitting targets up to 72 kilometers (45 miles) away.”
Maybe it comes down to Russia having a much bigger air force.
The other thing to consider is what’s being targeted? Ukrainian infrastructure.