Food for thought: would you call someone who buys Tesla stock a Tesla user?
You can use a Tesla without owning Tesla stock but you can't use Bitcoin without owning Bitcoin

The question would be if you are a Tesla user if you bought a Tesla and then just left it in the garage.
Theoretically government could ask all exchange for identity of every user who perform KYC, AML or other identity verification method. With big amount of data, they could obtain minimum number Bitcoin user (with proper data reprocessing).
Jesus, don't give them any ideas please. The orifices of my financial life get probed enough as it is, thank you very much. Any more and I'll start developing a fetish.