I used to be a professional speaker (Amazon, VMware, etc), and presented at more than 600 events. They said I was pretty good. Point is, after years of perfecting my craft, I can instantly spot the difference between a good presenter and a "fake" / bad one.
Most people are bad. Really. Sorry to be blunt, but it is what it is. A bit of training and a bit of rehearsal would go a long way. I am shocked that big events like this one do not try to invest more in preparing the speakers. It wouldn't take much.
The audience is also able to detect professional speakers like yourself, with calculated hand movements and inauthentic voice pitch calibration and is equally turned off -- its just that professional speakers so rarely admit that since they make money off saying otherwise. The problem here is just that the topics aren't compelling enough. And you rarely get a good speaker who also knows the topic well so as to be perceived as authentic.
Look at Elon's keynotes, they are TERRIBLE from a public speaking perspective, but excellent content that generally is interesting. Also no one perceives them as inauthentic, just off-hand-ish. It works.
Most people are bad. Really. Sorry to be blunt, but it is what it is. A bit of training and a bit of rehearsal would go a long way. I am shocked that big events like this one do not try to invest more in preparing the speakers. It wouldn't take much.