>> At least in the early 2000s having a page on a high authority(however you define it) domain automatically guaranteed higher rankings.

I totally agree. And in all of those cases, the page that is on that "high authority domain" has INTERNAL LINKS from other pages of that site. The site has high authority because other high authoritative links point to that site. And that site links internally to that page. That's why that page ranks.

That's completely different than having an orphan page or an "orphan site" (a set of orphan pages) that are on a highly authoritative domain. Just because those orphan page(s) exist on an "authoritative domain" doesn't mean that it will rank. Even 10,20 years ago that was the case.

In the case of this AWS site, the Amazon S3 page(s) that rank, they're orphan pages. I may be wrong, but if you go to the home page of that amazon domain, you can't click through to the page or pages that are mentioned in this original post.

Just because the orphan pages(s) or orphaned "site" is on an amazon domain, doesn't give it ranking power--because "domain authority doesn't exist.