I've been in Computer Science graduate courses and lectures in one of the top programs in the US where it seemed like every week the first 5 to 10 minutes was spent trying to get the projector to work with the lecturers laptop.
Sounds like you are having network issues/bit errors? You are breaking up.
Sounds like your bluetooth is having issues? You are breaking up.
Sounds like they are mobile, and in a weak service area? You are breaking up.
Any type of problem like that ultimately becomes a "5 Whys?" kind of troubleshooting to get to a real root cause, and from a end-user device you generally don't have the necessary access or data to answer more than 2-3 layers of abstraction.
That is like a relative saying you are not an IT expert because you don't know immidiately what the distinct root cause of "the screen being black" is.
Who knows where such a thing comes from? It could be any number of things on a huge technological stack distributed over a large geographical area.
A domain expert should of course be able to distinguish various bad conditions by ear, e.g. clipping, saturation, wromg microphone distances/orientation, signal interferences, hum, bad grounding etc.
But not all people are good at analytical hearing regardless of them being engineers or not. That is why people pay the likes of me.
My biggest complaints about this approach are that I can't easily see speaker notes (I have a fiddly workaround that I can use if I need it, but it would be nice if Google Slides would support the ChromeCast use case a little better..) and that the TVs/projectors tend to screw around for 10-15 seconds before automatically choosing the right source.
I can get a speaker notes and a normal presentation tab open and cast one of them, but they all jump around and do the wrong thing on my screen (wanting to maximize, etc) and require a lot of coercion; too much time to start a normal lecture.