Not really sure as it is a complex system and Google isn't necessarily the most transparent when it comes to these issues. Why are you asking, is your site taking a long time to be crawled and indexed?
Google may crawl pages slowly if a site is new, has low trust, few external links, or lacks unique content. If a page doesn’t appear valuable, Google may crawl it less frequently or may not index it for a long time.
Therefore, it’s important not only to check the technical aspects but also to improve content quality, internal linking, and gradually build trust in the site.