Google is not a search engine. It is a curation service. It only searches this collection of data that it decided was worthy of curation. Google tells us this

Google is not a search engine. It is a curation service. It only searches this collection of data that it decided was worthy of curation. Google tells us this is for the best. We are forced to take their word for it since their algorithms are not public. Google tells us this is also for the best.