Since it has been over two weeks since the ability to filter articles by category was almost completely removed, and I have seen no action to remediate the change on the github despite this comment, I have decided to post links that will take one to the article page filtered by the selected category.
Update: There is now a PR waiting on github to restore the category bar to articles. https://github.com/civitai/civitai/pull/4605 It's already Thursday so I don't expect it will be merged and deployed before the weekend.