My model friend broadcasts on 5 different sites simultaneously, as per her studio contract.
She has told me that she does not have time to respond to every tip personally. Her studio admins respond in chat for her, and from what I have seen of the chats on at least two of those sites, the responses are automatic. The admins may even be using bots, but this is just my theory.
For example, a tip of X amount gets X reply. The reply seems to be tailored to the amount tipped and is the same every time.
She only replies in PM to members who tip for it. Now on CB for example, the price for PM is 10 tokens. Sometimes, when her room has hundreds of viewers, she responds in PM to the highest tippers or to regulars that she knows and likes.
She does not respond to "greys" at all, and her admins act as mods for her.
It has taken me months of visiting her room to understand how she operates, and while I don't really blame her, I can understand how this would be off-putting for newcomers to her room.
I don't know if this is helpful to the discussion, I just thought I would put it out there to help to understand.