There's has been a mini resurgence in C from (normally high level language) programmers who are getting sick of web development and are interested in data oriented design.
Conference benefits could be:
Pushing the C standard. C11 is barely supported.
Discussing new standards in a forum other than mailing lists. Did you guys know there is already a C17 standard?
Letting old C devs pass on their wisdom to new C devs. C has a lot of pitfalls but also has a lot of neat tricks.