It is necessary in a community that wants its users to interact correctly. Usually in a community, it is often "followed" by prominent and prominent users. I consider it necessary to also notify the community activity of the users that I follow (including the user's birthday notification).
The "add as a friend" option is essential, because when you have ties with a user in a community. It's good to stay together. Interact more. And also receive notifications about this user, and be able to post on your profile with comments.