A photograph shows what the seller decided to show. A live show lets you ask for what they did not.
That is the entire argument, and it only matters for things where condition is not uniform.
The three that make the case
A trading card. Two cards photographed head-on look identical and are two grades apart. Ask for it tilted to the light and the surface tells you in one second — whitening at the corners, a crease, a print line. Nothing flat shows that. What do NM, VG and the rest mean?
A saree. The drape is most of what you are buying and a photograph cannot carry it. Held up, moved, held against the light for the weave and the zari — that is the thing itself rather than a picture of it.
A sneaker. The question is always the midsole, and age kills adhesive whether or not anything was worn. Ask for a flex. A photograph of a deadstock pair tells you nothing about whether the sole will crumble. What does deadstock mean?
Why it is not just better photography
A seller with a tripod and good light can produce beautiful photographs of a flawed item without lying once. They chose the angle, and the angle that hides the chip is also the angle that flatters.
You cannot choose the angle. You can ask them to move it — and that request is what a photograph cannot answer. How to ask a seller about an item, live
The second thing live does
It makes the answer public. A question answered in the chat is answered to the room, and it becomes part of what was claimed about the item. If a seller says "no chips" out loud and there is a chip, that is a description, and descriptions are what a dispute is decided on. What if the seller lied about the item?
A private message does not carry the same weight with the room, and a photograph carries none.
Where live adds nothing
New, sealed, uniform goods. There is nothing to inspect, and a show is a slower way to buy something you could have searched for.
So the format is not better in general. It is better for a specific kind of object, and that kind is most of what people collect.
The thing most buyers never use
Asking. Rooms are full of people watching silently who would have bought if they had asked one question.
The question is "what is the worst thing about it?" Five questions worth asking before you bid
More: Metzee vs an ordinary marketplace listing, how to judge an item through a camera, how a live auction show works.