How to hide all disabled products category, what is the best practice to achieve in Magento 2.3.4?
Where do you want to hide your category ?
If it's in the filter then it's the native magento behaviour to hide them when they have no products.
If it's not there, then you probably just need to override the template calling the category like in your menu, and use a count condition on the category items.
An other work around would bo to override the controller that call the category and if a category is called with no items you can do whatever you want. (Because even if you can't see the category it doesn't mean that your Jean Kevin user can't enter his path in the adress bar.