alt Hacker NewsThinking of an algorithm in the abstract is one thing, implementing it at scale is another.
Yes you could have invented PageRank, but could you also have invented MapReduce, BigFiles/Google File System (GFS), Google Web Server, Bigtable, Protobuf? Then spun up fault-tolerant clusters consisting of cheap commodity PC hardware in an era where AWS wasn't even an idea yet? Then invented the concept of Borg to manage this hardware globally?
When Google started, Beowulf clusters were all the rage. So it wouldn't be a big conceptual leap at all. But productionizing it is serious work.