Google search as we are all aware will Crawl and Index the webpages on the World Wide Web and start showing up on searches based on the users’ search intent.
When there are more unique pages on Google for any website, that site starts ranking higher for more keywords resulting in more SEO traffic and user engagement.
On Contrary, when the pages are getting reduced for a given website from the Search engines, then it means it got some serious problem. In an SEO perspective pages are deindexed due to many reasons. One such reason in reacent article on SEJ: Google Will Deindex Pages If Site Is Down For Several days. Also, other reasons for deindexing is redundant pages. These are common on large website portals where there are 100s & 1000s of webpages.
