If you don't have the private keys, they're not your coins.
For cryptos, the law doesn't make this promise for you, and even if they do, crypto being mathematically secure, the courts can't just declare an outcome that cannot be achieved in reality.
Finally, look up executive order 6102[0]. Where by decree due to those "evil" people who where hoarding their savings (as they should) got their gold seized.
The larger issue at hand is that some people believe they are better and smarter than others and therefore, they ought to have more control and say than the ignorant public.
I on the other hand do not know, nor presume to know, what is better or worse for anyone but myself.
Like I said, I'm not a fan of EO 6102 so I'm not necessarily one here arguing the government knows better than everyone else what to do with your wealth. I'm just arguing its not great for society if everyone just digs their own hole to store their acorns indefinitely. Its better for us to actually use our wealth instead of hoarding it away in negatively productive places.
I have a good bit of savings and retirements. Very little of it is in "money". Most if it is in some kind of productive asset actively building wealth not just in my investment but with the rest of society overall. If your retirement is based around holding a lot of paper (money) in a box under your mattress you're gonna have a bad time.
https://www.nytimes.com/2019/07/19/business/safe-deposit-box... / https://archive.ph/DWsWh
The nation state of Venezuela can attest to that
1. This makes them utterly useless, because it turns out it's essentially impossible to transact without trusting a third party with those coins at some point. Unless you have literally mined every coin you've ever used, and never used escrow - the "Code is law" argument as above is a terrible paradigm for social transactions that require some form of trust. We have literal centuries of legal code built to attempt to resolve this precise issue for real tender, and crypto is a shitty, shitty attempt to replace it.
2. It turns out most of the "crypto crowd" isn't in it for using these things as actual currency, they're get-rich-quick fuckwads, and the actual ownership of the coin mattered very little when it was just an investment vehicle they were planning to convert back to dollars at some point.