From the threads I've read, the block list is the thing that decides it, though the older established sites rarely say so. Are there any sites like cam4 that allow multiple broadcasters on one screen — seems like a simple question but I keep getting mixed answers depending on where I look.
Keep the first message short and specific, because you learn more from one real chat than fifty swipes, and it makes a real difference. The free tier and the daily match cap pull in opposite directions, which changes the whole experience.
The verification step and the search filter setup pull in opposite directions, so results vary more than you'd think. After a slow start the niche ones have cleaned up the fake accounts a little, though it settles down after a while.