"can't" doing a lot of work here
Buying #bitcoin to hold in a government registered retirement account you will be fined for withdrawing from without their permission seems like an incredible idea because if you are like most people, this is the largest pool of wealth you will ever have access to and investing it in the best performing financial asset in history is a no-brainer, and also because if worse comes to worst and you need to access your savings you can give the feds the big ol' middle finger, sell those assets, and there isn't a god damned thing they can do to stop you from spending your own hard earned uncensorable, unconfiscatable money.
FTFY