We're definitely getting there and exchanges (Binance, Poloniex, etc.) closing registration because they can no longer handle more users is a proof of that. I say we give bitcoin one more year, after that, almost every service will be in the process of adding it as a payment method (assuming that we will have LN stable and working by then).
Thats true that no more registration accept in binance and bittrex prove that we are maybe in second stage.
But this is not at the end of the stage. Still too early to speak about crypto can change fiat.
Every year is different stage with crypto markets and you could see it if you track back the past price and the current price of each alts you handle for these past years and even with bitcoins the growth doesn't stop with it so I can say these events can really tell that we can't determine on where are we right now in crypto map since looks like these growth is endless. And I never saw that crypto will end up the fiat since fiat since there are so many factors that needed to consider for this thing.