I would disagree that we're better off. Well, maybe some people would be. But personally, that information has actually had the ironic effect of making me more effective at using my 'free will'. It's easier to try and be something other than what you are if you believe you think you have more control than you actually do, and that's a potentially huge waste of energy.
I don't think disbelieving free will requires nihilism. It's not that there's unfreedom of the will, it's that the idea and its converse never made any real sense.
> We’re better off believing in it anyway.
Nihilism is easy to start but hard to finish.