My professor once told me he presented at a small conference, the whole audience everybody had PhD in mathematics and maybe 2 of the 50 or so people in the audience could follow along. The point he was trying to make is at some point the people in the audience were not really interested in what was being presented because it is difficult to just follow along some really niche topic.
He discussed this topic and how generally it's left to those who are more notable in a field to ask the 'dumb' questions everyone else is afraid to ask. And such questions often need to be asked to get the audience on board and open the floodgates with areas of niche research - the speaker themself is often too far into the rabbit hole to discern the difference between opaque and obvious.
So it stands to reason, at smaller conferences this would be a big problem, with fewer thought leaders in attendance whose reputations are intact enough that they wouldn't mind looking foolish.