I was wondering, since nobody never (need to) go to the third pages (most cases neither the second page), why Google just don't limit the results to the first two pages?
Because it is not true that it is never necessary to go to the third (or later) page? (Especially since the first two are often full of sites just replicating content from higher-ranking pages, be it different mailing list articles, "Q&A" sites that copy content from stack overflow, ...)