In reply to Alex Belov.

If you develop a site for a client, hiding unnecessary features is helpful, makes the backend more user-friendly and prevents misunderstandings. Especially when the person who will manage the site isn't very tech-savvy, those features might end up being confusing. I remember being asked "why is there a comments section in my admin? I told you I don't want comments on my site".

BTW, here is a nice article on the subject: https://www.smashingmagazine.com/2016/07/how-to-make-wordpress-hard-for-clients-to-mess-up/