The site is one of the places authorized by the FAA to do required TRUST certificates for non-Part 107 drone flights, and Greg here is a well-regarded instructor-so quite legit and all.
You can also get the non-flying part of a private pilot’s license through them.
Well, there's definitely some SEO involved, because the site sells ground school courses for various piloting and drone flying subjects, as well as some free ones on specific hardware (like https://pilotinstitute.com/course/cessna-172-deep-dive/ about the Cessna 172). The courses are pretty good from what I've looked at with their drone stuff, though.
...Which is really sad, because it actually reads like a earnest author just trying to make their informative page visible.