In an AskGooglebot session, John Mueller was asked about why, when using the site:query operator on Google, all of the URLs are not present when the results come up.
The SEO professional is referring to the site:query operator, which when used as follows:
the Google results will bring up all pages on the somewidget.com website.
John explained that the site:query operator is not designed to return complete results, nor is it meant to be used for diagnostic reasons.
He also added that Google Search Console is a much better choice to use for site owners who want to find out more information for diagnostic purposes(such as for a website audit).
Don’t rely on the counts showing up in the Google search results, because they are not reliable and aren’t the best source of information for someone trying to diagnose indexing issues.