Requests to lock phones away at comedy shows are frequently read as star behaviour. The reasoning is practical and specific to how stand-up material is built and sold.
A joke only works once
Surprise is the mechanism. A punchline produces laughter because the audience did not see it coming, and knowing it in advance removes the response almost entirely.
A clip circulating before a tour ends means part of every subsequent audience has already heard the joke.
Unlike a song, which people want to hear again, a joke is consumed on first hearing, and that difference drives the whole policy.
Recorded material cannot be sold twice
A stand-up special is the commercial product of years of touring, and its value rests on the material being new to the viewer.
Once significant portions are available as clips, the special is competing against free versions of itself.
Retiring an hour after recording is already the convention, so material leaking early shortens the earning life of work that took a long time to build.
Unfinished material looks worse than it is
Comedians work out new jokes in front of audiences, and a joke in development is often clumsy, over-long or missing its ending.
A clip of that attempt, removed from the room and from everything said before it, misrepresents both the joke and the performer.
The risk of that misrepresentation makes comedians reluctant to try anything genuinely new, which pushes them towards safe material.
Crowd work is the most exposed part
Improvised exchanges with an audience depend entirely on the room, and a line that was clearly playful in person can read as hostile in text.
The audience member being spoken to is also identifiable, which introduces a consent problem the venue cannot resolve afterwards.
Comedians who build shows around this material have the strongest reason to restrict recording, because their act is the least reproducible and the easiest to misquote.
Why pouches rather than requests
Verbal requests work on most of an audience and fail on the part that matters, and enforcement from the stage stops the show.
Lockable pouches move enforcement to the door, where it is a condition of entry rather than an interruption.
The side effect is an audience with nothing else to attend to, which performers consistently describe as producing a better room than the policy was designed to create.