In fact, OSM is perfectly capable of representing lane restrictions (http://wiki.openstreetmap.org/wiki/Lanes) and some of the existing OSM clients (such as OsmAnd) offer 'lane assist' (arguably, it might not be as good as Google's but there's no fundamental problem in achieving feature parity).
And while the GMaps feature of offering you route alternatives based on the current traffic is nice, the "price" you are paying for it is unconditionally sharing your location with google while the GMaps app is running (or even at all times, depending on you settings). I personally don't feel comfortable with that compromise.
Sure, but if you're going to make that argument, all software is equivalent, because you can just implement the stuff you want and delete the stuff that gets in the way.
No doubt, real time traffic information can be developed for openstreetmap. But if and when it happens depends on where others drop the ball.
For example, current navigation systems built into cars tend to be completely out of date and mostly unsupported long before the car itself is end of life. So this is an area where openstreetmap might take over.
Though since OSM predates Google Maps, it makes sense that OSM would have another first :P