I was around pre-Google.

Ranking was Google's 5% contribution to it. They stood on the shoulders of people who invented physical server and datacenter infrastructure, Unix/Linux, file systems, databases, error correction, distributed computing, the entire internet infrastructure, modern Ethernet, all kinds of stuff.

And none of that had to do with learning from other search engines…

Eh ... I question that 5% ranking is google's only contribution, even if it was important.

Everyone stood on the shoulders of file systems and databases, ethernet (and firewalls and netscreens, ...) Well, maybe a few stood on the shoulder of PHP.

Google did in fact pretty much figure out how to scale large number of servers (their racking, datacenters, clustering, global file systems etc) before most others did. I believe it was their ability to run the search engine cheap enough that enabled them to grow while largely retaining profitability early on.

More specifically on that last point, I remember reading something like Google's biggest contribution hardware-wise was using lots of cheap, easliy-replaced distributed storage with redundancy instead of expensive large singular storage with error-correction? Or maybe it was memory and not storage. Whatever it was I remember them not caring as much about error correction as others, and being able to use relatively cheap hardware because of it.

Yeah, I remember the moment search engines invented computing, I cannot look at sand the same way anymore /s