All else aside (since other commenters have covered every other thought I had and more) it's worth noting that Ukraine is also fielding S300 class kit and this has likely been a significant contributor to Russian aircraft losses.

It also appears that in the Russian case either the S300 itself or the training of the crews has not been particularly effective against the Bayraktar drones, which I'm not aware of Russia having an equivalent of to use against the Ukrainians.