I'd love to see that number broken down. I expect it to be mostly "used cryptocurrencies", not traded them, and those cryptocurrencies to be mostly BTC and ETH, possibly XMR, but not some utility token of an exchange.
The number of Americans having any money invested in the stock market in any form (i.e. including 401k, mutual funds etc) peaked at 60%. I'd be surprised to see people trading/investing in crypto to be > 3%, but who knows. Annoying that they just have these broad questions. "Have you, at any time in your life, ever eaten solid food or murdered a president?"