I was playing around in SEMRush and Keywords, getting more comfortable with using it as a tool. So I picked a random long keyword from the list of the domain that I picked out and looked at the page it was for. Went into the page and found it ranked for 300 keywords. Intrigued, I opened the page to see what it was and the shortest most simple 200 word article was all that was there for content.
How did this happen?
I've seen guides that suggest 2-3 keywords per article, with some length and content, I've also seen people that reply in those guides saying they can still outrank with lorem ipsum. Regardless, this is over 300 keywords in an article with only 200 words in it. What's going on?

Is this the penultimate goal for SEO or just the effect that a well-established website has on SERPs? Did they 'crack the code' of Google, or is this normal for a domain that large with an article that's aged?
How did this happen?
I've seen guides that suggest 2-3 keywords per article, with some length and content, I've also seen people that reply in those guides saying they can still outrank with lorem ipsum. Regardless, this is over 300 keywords in an article with only 200 words in it. What's going on?
Is this the penultimate goal for SEO or just the effect that a well-established website has on SERPs? Did they 'crack the code' of Google, or is this normal for a domain that large with an article that's aged?