Odds are, when you watch my HILARIOUS video, you will not laugh. Does this mean I wasn't funny? NO. Does it mean you don't get my sense of humor? Perhaps, but not necessarily.
What it means, plain and simple, is that standup is a live performance art. It doesn't translate well (if at all) to video.
That's due to the psychology and the contagiousness of laughter.
Basically, if we haven't seen a standup comedian in person...we simply haven't seen them at all.
How do comedy bookers decide if a comedian is funny enough for their show?
They know videos don't trigger individual laughter. So they put aside their personal preferences and simply count the number of seconds of laughter per minute (also known as the Positive Audience Response or PAR score.)