The WordPress admin bar is useful for administrators, but it can be distracting for subscribers, customers or other non-admin users.
Recommended behavior
Keep the admin bar visible for administrators and hide it for everyone else. That preserves quick access for site managers while improving the frontend experience for regular users.
Where to place the code
Add the customization to a small site-specific plugin or a child theme. Avoid editing WordPress core files.
Why not hide it for everyone?
Administrators often need quick access to edit pages, clear cache, review updates and inspect logged-in behavior. Hiding it only for non-admins is usually the better balance.
Testing
Test with an administrator account and a regular user account to make sure permissions and frontend layout behave as expected.