Disable Categories for Posts
Removes categories from posts: the Categories menu, the editor panel and the column in the posts list.
Snippet Library
Disable Features snippets for WordPress
Snippets that switch off WordPress features you do not use: comments, the block editor, RSS feeds, automatic updates, attachment pages and more. One snippet per feature, so you turn off exactly what you want and nothing else.
Disable Tags for Posts
Removes the Tags taxonomy from posts: the Tags menu, the tag box in the editor and the tag column disappear.