There was no way to know how much gold or silver there was above ground or in circulation for a very long time while those were money, there's no way to know how many dollars there are, no monetary medium has ever had anything even kind of close to the certainty that bitcoin brings in this regard, and yet price discovery has carried on throughout the whole time. Bitcoin may not be perfect in this, but it's an incalculably gigantic improvement over anything else we've ever seen, so if this presents an issue with price discovery, and that's a big if, then this will also improve dramatically. This is a point in favor of Bitcoin, not against it.