Well, why compare with Serbia? Compare with Gulf War!
NATO had better planes versus worser systems (Georgia had better and more modern SAM than Iraq had, even adjusted for all the time passed), there were no limits for NATO aircraft, yet NATO losses (especially in the first days) were very high.
Serbia bombing was only that effective because NATO got great real-life SEAD experience and Serbia had even weaker AD than Iraq had, while also trying not to take unnecessary risks.

Considering this, RuAF having only about 6 losses without having any true SEAD experience and versus systems one generation newer than USAF faced is a success; either RuAF was better than expected, or Georgians failed at using their quite capable (relatively at least, Iraq and Serbia had worser) systems. Or both.