I am not without sympathy towards you though. I have no doubt you have the personal talent to clear it. More than actual skill checks, the current T9 bottleneck also test out the strength of your connections within the game. It's mainly due to there being a lot of people in content they can't handle (T5->T9 yoloes).

The same social connections thrive in FCoB as well, although I can see it getting easier on the next patch with the df introducion. However, I don't expect df parties to be able to clear anything above T11 unless they (hopefully not :c) go out of their way to nerf the content.

Tl;dr More bottle necks means better players in the gaps in general. Better players-->better runs-->easier to form solid parties--> easier to clear it. Having onlu a few bottlenecks only benefits those who are just barely on the skill check and can expect to be semi-carried.