Edit the past pages with new content and fixed tags and add some keywords cluster then try again .
what you mean "fixed tags"?
What does it say in GSC, any errors or warnings? In general, you should be able to identify the problem via GSC. Depends on what kind of content you have but since they were published in 2018 updating content and improving quality wouldn't hurt. Submit it to google for indexing again.
you should resubmit index on GSC, and more tool same: sinbyte, 1hping
There can be a few reasons. 1. Google might have reclassified the pages as outdated based on their ages. Try updating the content to make it more relevant to the current trends. 2. Check for broken links or technical errors on the pages that might be preventing the pages from being indexed correctly. 3. If you made significant changes to the website structure recently it might be affecting the crawling and indexing. Try using GSC (Google Search Console) to identify any other issues on the website.
To resolve this issue, check for issues like noindex tags, canonical tags, or thin content that might be preventing indexing, and consider updating or adding fresh content to the pages to improve their visibility in the SERP.
