Category pages vs tag pages — one of these is index bloat

Category pages vs tag pages — one of these is index bloat
WordPress site had 400 tag archives indexed, each thin, all cannibalizing the categories.
— Categories: hierarchical, few, deliberate. Real landing pages with intent. Index these.
— Tags: flat, many, auto-spawned, usually one post each. 90% are thin duplicate slices of category content.
The move: noindex all tag archives, keep categories indexed and built out with intro copy. On most sites tags are a UX convenience, not a ranking asset.
Before you noindex tags wholesale, check GSC — if 2-3 tags actually pull traffic, convert those into real category/hub pages instead of nuking them. Don't throw away a ranking page on principle.