The ones I've seen in wide use literally are "load page, click on Stream 1, it starts, if it breaks/looks shit, click on Stream 2 and repeat until good stream found", and also filled with ads, so I'm guessing they mostly run on ad-money. Most visitors aren't really technically inclined, I think I've lost count how many times I've helped people install ad-blockers once they try to get a stream running while a group of people are waiting.
Not usually, it's more like a 90's porn website setup, where you're going to click in a ton of fake links and close popups for a while until you reach a 720p stream.
Think that it's usually a bunch of very temporary services that popup and are taken down quickly, as well as a bunch of not-technically-pirate-themselves hubs that link to the former. There's not enough stability to set up payments, which are also traceable.
Anti piracy measures are crazy though. La liga has gone as far as to listen in microphones on user's apps in the hopes of catching hidden audio tones that, crossed with geolocation, allow them to detect streaming spots.
It's like gamers with anti cheat, a situation where the measures are both technically impressive and absurd overreach in a legal/moral sense.