This is an absolute farce. Maybe talk to us when there are no longer reports of being able to easily scam someone out of all of their money with a non-reversable transaction just by sending them an image with a script in it.
Someone could make a service with delayed settlement that is denominated with Bitcoin, and it would work just the same.
If you pay someone with a $100 bill, your only recourse is to ask for them to return it: the same as Bitcoin.
Bitcoin is subject to federal policy as much as anything is: as much as secret Swiss bank accounts.
You imply evasion works. But that certainly doesn't mean it is federally legal, legal with the IRS, or legal for whatever other reasons. You have the risk of serious consequences if you are caught breaking the laws that apply to you.
Your argument implies that you can break the law without getting caught, but we already have surprising crypto counterexamples against that.
Also, the market is slowly being split into legitimate trading (via centralised platforms with KYC rules) and illegitimate trading (for stolen bitcoins, or bitcoins tainted by tumbling with illegal bitcoins). As that plays out, it seems likely to become more difficult to actually trade your crypto without some laundering costs and risks.
Keeping a number in your head or hiding some gold in your secret location are the same thing.
I suspect a lot of more of the 0.1% have gold hidden than many would expect. I've met two eccentric 100 millionaires that advocated for hiding gold as a wealth preservation mechanism. I think this is becoming the primary non-trading use case for Bitcoin - met both of those individuals through conversations about crypto.
Is this a fantasy that few if any people will ever utilize? Sure.
Is it also super cool? I think so.
I think the main demand of bitcoin is "money that isn't subject to federal reserve policy". No fiat currency in the world is effectively accomplishing that today.
(Note: I had to stop using brainwallets three bubbles ago because I had recurring nightmares of getting a brain injury and losing access to my funds. Don't recommend it.)