Imo the reason there are so many websites is because there is no one answer and I think most people who spend time with these websites are somewhere between trying to find a nonexistent shortcut past actually understanding the content, and just procrastinating. What works for one person is totally useless to the next.

For the record I am very aware that it's easier for some people than others, I've been in higher education for 8 years with ADHD. That doesn't make me an expert on studying, probably the opposite, but I've tried lots of methods and personally only ever found them a distraction from the difficult but relatively straightforward task of just learning the stuff.