I launched a new website, submitted a sitemap on Google on 09/03/2021. But for some reason out of 18K+ pages, only 1.2K pages got indexed. See the screen dumps below, not sure what is the issue.
The inspect URL result below for one of the not indexed URL:
Hey @fragranzaUk ,
It looks like the pages have been Discovered - currently not indexed. This means that Google did crawl your site and found links to the 17.8k pages (making them discovered) then put them into the queue of sites that Googlebot may eventually crawl. Since the web is virtually infinite and there is a prioritization, it may never actually get there. Googlebot decides what to crawl and index based on PageRank and it seems as though Google found enough PageRank in the 1.2k pages that it did index but not enough in the others. Googlebot could have based this decision on a lack of internal links to the pages, a lack of unique content on each page, low overall quality of the page, etc. Google's indexing system is a machine learning algorithm. And so it may decide not to index some pages sometimes for a variety of unknown reasons.
If you are wanting more of your pages to be indexed, I would suggest including unique product descriptions on each product page to tell Googlebot it is a unique page that is worth indexing. That being said, doing that for 18k pages seems unreasonable so I would run your site through ScreamingFrog to get a better understanding of which pages were indexed and which were not. Make sure your MVP products are being indexed first then go from there.
My team put together a great article about this that you can find here.
I hope this helps you. If you found that it answered your question, please give me a thumbs up!