What this site uses for?

What is the purpose of using the information here?

As a web search engine, it is seen as collecting information about routers or specific web servers and making judgments about vulnerabilities and exposures to external operational information for the purpose of diagnosing vulnerabilities.

This product provides information based on IP. It’s seems an search engine that can check vulnerabilities of devices connected to IP. For the good will, it would help mitigate vulnerable vector or misconfiguration workloads earlier from threat actor. But in other words, it could be a gold mine for them also.

OSINT is defined by both the U.S. Director of National Intelligence and the U.S. Department of Defense (DoD), as intelligence “produced from publicly available information that is collected, exploited, and disseminated in a timely manner to an appropriate audience for the purpose of addressing a specific intelligence requirement.” that produced from publicly available means it’s too public, opened already for hackers to exploit it for cyber crimes. So it can’t be a gold mine for black hat. They’re gathering the source from more more deep.

Maybe It could be used in blueteam for research, or maybe in pentesting for ethical hackers.

why people use shodan, same.