What do you mean they're not relevant? The top result you linked contained the word stackoverflow didn't it? It's showing you exactly what you searched for. Why would you need a search engine at all if you already know the name of the thing? Just type stackoverflow.com into your address bar.
I feel like Google-style "search" has made people really dumb and unable to help themselves.
the query is just to highlight that relevance is a complex topic. few people would consider "perl blog posts from 2016 that have the stack overflow tag" as the most relevant result for that query.