Killed 800 tag pages. Rankings went UP.

Killed 800 tag pages. Rankings went UP.
Client's WordPress auto-generated a tag archive for every tag ever used. 800 thin pages, most with 1-2 posts, all indexed, all competing with the real category pages.
This is index bloat. Google crawls the junk and trusts your whole site less.
The move:
— Noindexed every tag and author archive. Kept them for users, hid them from Google.
— Removed them from the XML sitemap entirely.
— Kept ~10 tag pages that genuinely aggregated useful content and had search demand. Made those real.
— Pruned thin date archives too.
Within two months crawl shifted toward money pages and core terms climbed.
Watch your sitemap plugin. Half of them ignore the noindex and keep listing the URLs. Manually verify the sitemap doesn't contain what you just hid.