User Affinities provides utility to show how much you've interacted with other users. Opening the modal shows only friends and servers you're a part of, Opening a user profile or popout shows them even if you're not friends if you're interacted with them.

Modal Friends:

Modal Servers:

User Popout:

User Profile:

To use this plugin you'll be prompted to enable a setting for allowing Discord to personalized your experience, this is required for the list to be populated:

If you've just enabled the setting that is required for the plugin to populate the users and servers affinities, you will need to wait 24 hours for it to populate the list.