Cons to using sub-categories?

I’m reorganizing our categories - we have quite a few and I’d like to pare it down, but with all things deeply technical, there’s a lot of nuance in the posts. I thought adding more sub-categories would help me organize the posts while still keeping things searchable.

Is there a downside to adding sub-categories (as opposed to using tags or increasing the number of categories?) My main goal here is to make our community easier for users to search and find answers.

There’s a lot of good info in the blog post