Most crypto is traded outside of the US though; most of the volume is on Binance and Bitmex. In this sense they cut themselves off from many customers. The advantage of their business model seems to be that with less competition from other US-law-abiding exchanges (because there are so few of them), they can charge much higher fees: Coinbase fees are higher than most large non-US exchanges, and Gemini fees are insane, something like 1% per trade.