Explain to me why would they need to store all this data

1B search queries are made every day using Google. If the average length of a Google query is 10 characters, that's 10GB of data logged only for the query itself. I'm assuming they optimize the way the store it to avoid repetition in other information about the query like information about the user, browser, etc. and compress it but still. Now factor in other data like visiting websites, watching youtube videos, e-mails, uploading files, downloading files, logging in, logging out …

characters data google information length privacy query repetition search store