Bitcoin is being used by everyone who held long enough to see over 5x return. Both as savings account, an investment, and a checking account for occasional purchases.

It is also being used by all sorts of international freelancers being paid in Bitcoin, although, most of them convert into fiat swiftly to pay bills. So they are not contributing to holding. But Bitcoin is useful for them, as it's a much cheaper and safer way to pay and get paid internationally.

Everyone else is a speculator, sitting on their stash, waiting for price to climb up. That's pure speculators/investors, who use Bitcoin to diversify their porfolio of whatever else they got. And as such, Bitcoin is highly useful, as it provides virtually unlimited upside with limited downside.