What makes a great difference is search quality is blocking sites you don't like/don't want to see. This propagates across all types of results (eg images/news too)

I use lenses for specialised searches (I have one for HN/Reddit) ND recipes (to avoid spammy sites). My favorite lenses are "non-commercial" (to surface results from the non-commercial part of the web) and "forums" (usually similar thing but focusing on human comments).