Checking my Search Console Tools recently, the number of "Crawled - currently not indexed" pages across all my sites has risen sharply recently, especially on s

Checking my Search Console Tools recently, the number of "Crawled - currently not indexed" pages across all my sites has risen sharply recently, especially on sites where the age of the content is more than a few years. I put a fair bit of time into trying to improve the sites with JSON-LD and breadcrumbs and what not. It seems to have helped just a little bit. I don't make any money off any of it, but it's still kind of irritating that no one can find it.