I have always deleted apps off my phone but still suffered from access via web.
My solution for X is to logout. This is enough since un-authed has no content and the login screen is enough to stop me.
Then for Youtube/Reddit I blocked on personal and work laptops by adding to /etc/hosts file. If I still had access to un-authed Youtube/Reddit homepage I would still find a way to enjoy it. Also Unhook is too easy to disable for me.
Then for my iPhone I have added both Reddit and Youtube to restricted sites via the iOS settings.
Works well so far.