While some platforms are more free and open than others, our livelihoods are all somewhat dependent on third parties. Hope for the best and plan for the worse.
I disagree about email filtering. A friend sending another friend an email that says, "Check out this cool thing I saw" does not get filtered by anyone. Email that borders on spam gets filtered, sure, but overall, email serves as one of the most open communication platforms we've ever had. It's a drastic difference from Facebook or Myspace.
To give a concrete example: a few years ago, I set up an email server in my garage using an old computer that was being thrown away at work. I used all free software. It successfully sent email. None of my emails were blocked. I engaged with my social network, (my "friends") using it. If my ISP had blocked my email sending, there were many, many other providers willing to send my email for the price of the connection. Given that spam cannot be eliminated, despite decades of trying, I think it's fair to say that I won't run out of alternatives, especially given that the email I want to send is innocuous.
By comparison, I cannot set up a Facebook server in my garage. If Facebook blocks me, I'm done. If that was my livelihood, I'm fully screwed.
My ideal is not to entrust my livelihood to any third party.
Obviously, it depends on what I want to build, but so far I'm happy not using any social platform beyond, say, email. The free, open platform of the Internet, LAMP stack, a web framework, and search engines is fine for me. I almost, but not quite, regret the time I've put into using Facebook at all, never mind basing my livelihood on it.