I don't think that's entirely true that you need all of those things to get hired. Your resume still speaks volumes about you. It's just that things like github and stack overflow show an interest in engaging in the larger community of software development, and are a strong signal when evaluating a candidate. Having been on both sides of the table it's important to remember that the person hiring you is taking just as much of a chance on you being the right fit. I think anything makes that decision clearer is a positive.