It's def a chicken and egg question. Which came first, the price or the adoption? They definitely feed into each other.
Price is first because of speculation of the adoption. If adoption never happens, the price will tank. It if does, it will continue to go up. BTC didn't get to 20,000 because of adopt
BTC's utility crashed. Therefore the market crashed. If it didn't there wouldn't even be BCH. It crashed because the utility crashed, not because it was overbought.