Man you are coming across as super whiny.
Khyber still is Eberron's version of the Underdark and Abyss.
Eberron's Dragons are indeed elevated above the other settings dragons. Partially because their empire is still intact. FR's Dragons are much more solitary and their powerful empire collapsed as a result of their 1000 year war with the giants.
I do agree as well that Elminster in Hell does not sound like a good book.
Some of the Dragons empires Collapsed, some Dragon Empires survive on Returned Abeir and Abeir and on parts of Coliar. And their Dragons ruling city states on Faerun. Still none of these compare to Eberrons Dragon Empire for power or depth of knowledge.
Still the Elven Empires in FR aren't to be brushed off, they were scary mother******s, their high magic literal broken the planet and changed fate enough to keep causing it to break retroactively. If the Elves of Faerun had not self destructed by genocidal wars with each other, they would be able to destroy Eberrons Dragon Empire (and Eberron and themselves and Faerun in the process, FR Elves are crazy). In most setting Elves look at Tieflings are a disguisted by what humans will do, in FR Elves are like humans hold my beer ( Tieflings meet the Fey'ri). It's what makes FR elves the most fun Elves in all of Fantasy.