The rules are accepted by the novels writers, they even helped come up with the statistics to their characters.
Golbins have 4 hit points max. About anyone with some basic training could butcher them. You know... that's why they are the weakest monsters ever...
You said it yourself. Drow are good AS A RACE. 90% of the human population does not have a pc class. Dwarven just have a little higher constitution than human, wich help a little. 100% of the drow population is AT LEAST level 2.
Think about it, an army of regular human or dwarf would be in big trouble against an army of level 2+ drows. We are talking about 1-8 hit points +0 to attack characters against 1-20 +2 attack OR MORE, but they also have innate spells abilities, and attributes bonus. And you know what, they are level 2+, and they have a two level penalty. That mean that EVERY drow is in fact a level 4 character minimum. Every drow is worth 4+ humans or dwarf.
Ertu is a pit fiend. Yes, the most powerfull kind of demon, and guess what... he had 13 hit dices. That's right. The most powerfull demons are level 13 monsters. So of course Drows are lower in levels. They fear Yochlol, and Yochlol are level 6...
Your problems is that you don't see the numbers as they should be. You are thinking that characters level 5- are very common, 10 or so are average, and 20+ a little rare, while level 30 just rare. But that's not the case.
Level 1 characters are
very rare. And as I said somewhere, there is maybe 15 or so level 30 NPCs in ALL of the forgotten realms. Level 15 are as rare as what you consider level 30+ to be, if not more.
Elminster is level 35 and he is the most powerfull character of the forgotten realms. Do you think any drow commoner is as strong as him?
This is not Final Fantasy or Diablo. The Maximum level ever is level 30. Level 30 in Dungeon and Dragons is like level 99 in Final Fantasy. Do you think every drow would be level 99?