Conferences are places where people with overlapping interests meet for fun and profit. I know a married couple who met at a Drupal conference, and one of my closest friends now is a dev I met at a PHP meetup in 2006. I’ve been hired by a company I met at a conference, and used a tool I saw advertised there. Oh, and I also got excited about Symfony when I saw someone give a talk on it in 2011.
Guildhalls and mason lodges have been meeting for 100s of years for essentially the same reasons.
Ask not what the conference can do for you, but what you can do for the conference.