AWS uses TCP/IP internally. And DNS. And DHCP. And NTP. And ssh. And all those other standard TCP/IP or UDP/IP algorithms you may think of. Now, if you want to claim they have their own bespoke build system, then I'd agree with you there.
When I was studying for my BSCS, I worked at a University library, shelving books. I had two floors -- Deck 4 (Dewey Decimal) in the old stacks, and 4 West in the new building (LCA). I also occasionally shelved books anywhere else there was in the library that needed shelving. So, I know both of those systems pretty well.
Dewey Decimal is like Latin or Ancient Greek -- a dead language. Not really designed to handle modern inventions and newer technologies. It was a huge improvement for its day and it served us well in the past. But it didn't age well, and it didn't scale well.
The Library of Congress system is alive, like modern Italian or English. It addressed the major weaknesses of Dewey Decimal and although it has its own problems, it has continued to adjust and evolve as necessary. It also has scaling challenges, but at the really big sizes operated by the likes of the library of Congress or AWS, I find that everything has its scaling challenges.
For me, if I was running my own personal small library (which I probably could, given all the technical books I've bought over the years), I might be inclined to use the Dewey Decimal system. Or maybe the Library of Congress system. I'd have to test them both out and see which served my needs the best.
And that's what I'd suggest you do before you make any Herculean or Sisyphean statements. Try them both out. See what actually works for you. Then speak from your own personal experience as to what works for you and why.