Prompted by this question. My take is that the security companies and banks that offer identity protection services use the phrase "dark web" as a scare tactic to get you to subscribe. And then when they say they don't find your info in the dark web, you are safe. My guess is that most if not all dark web sites don't even allow anyone to scrape for info. "Legitimate" users of dark web sites will have exclusive access to the data store there.
Do these security companies provide any value by "searching" the dark web?