Earlier quoted context omitted.
You discount the entire category of users who don't "hold" any cryptocurrency at all, but use it as a medium of transfer - buying as much as they need and then transmitting it elsewhere.
As much as they need for what? Aside of ransom payments and drugs, you don't need to buy cryptocurrency, ordinary fiat money works just fine as a medium of transfer.
Exchanging cash for cryptocurrency without a bank inbetween is a pain in the ass, but its a hell of a lot cheaper than, for example, Western Union.