Rough thoughts:
Categories are forced to be disjoint, that one post cannot have two categories. It suffers when I have a topic about multiple technology topics or can be categorized different perspective.
For example, if I’d like to call for a release of multiple components since TiDB & TiKV & … use a simultaneous release model, I cannot found a good category.
Tags, in another way, can be used together tagging one post. I’d like to keep only meta concept categories, such as “meta” for topics on the forum itself, “ecosystem” for topics around the community, “community” for other non-development topics, and “development” for any development topics ( design, code, testing, document, etc. tagged in components ).
What do you think?