Good ranking is what made Google a trillion dollar company.

Google indexed the same sites as Altavista, but Google Page Rank made the right sites bubble to the top and made Sergey and Larry billionaires...

You’re right. But at the same time that quality seems to decline or at least stagnate. I think they face the hard problem of an decreasing signal to noise ratio.

Ranking is definitely easier when you also provide and moderate the content. That implies the technical solutions might differ qualitatively.

What I mean is you can't do

    select * 
      from table 
     where ts_query(...)
  order by relevance_metric

but instead do

    select * 
      from (
        select * 
          from table 
         where ts_query(...) 
      order by ts_rank(...)
         limit 1000
    ) 
  order by relevance_metric 
     limit 10