Huh? From what I recall, it's been pointed out many times throughout a variety of threads that the Convocation was not simply going off and doing its own thing with zero oversight and accountability. It wasn't a hive mind, either - since Elidibus' seat was designed to sometimes align with the Convocation on some occasions and against it on others.
There's also the conversation between the player character and Hythlodaeus during the Elpis portion of the story, as seen here:
https://i.imgur.com/7Pdc792.png
Note how it is pointed out that countless people from the world over vouched for Emet-Selch, rather than just the Convocation.
Their entire society is also built around research and debate.
I'd also point to this snippet from one of the short stories:
https://i.imgur.com/TJbbRgZ.png
An outright insinuation that debates are held in regards to the suitability of individuals appointed to positions of authority.