Well, if you are on a trajectory of a 30-year career job at one company with little to no changes in your income but adjustments and raises, then you probably don't need such a community. But judging based on Boggleheads forums, there's a need. Yearly re-balancing, changing your goals, windfalls, unplanned expenses, adjusting for tax efficiency, switching jobs, re-doing your portfolio because you did it horribly when you started, helping others who have a messy portfolio, and of course, the many questions every n00b has when they start.
Of course, Boggleheads would do just fine for any of these, but more options never hurt.
Of course, Boggleheads would do just fine for any of these, but more options never hurt.