The key problem seems to be to be how you quietly convert the crypto to real-world goods.
For example, you want to buy a ranch in Peru.
You pay the owner in crypto-currency anonymously, then you and the owner conduct a separate transaction in fiat for a much smaller amount.
So the visible portion of your wealth remains in fiat, but it is only an facade for the real financial transaction which occurred anonymously in crypto-currency
The fly in this ointment is that ironclad anonymity against the national security agencies is very dubious. How can you control when the person you bought the ranch from screws up his anonymity and TPTB rubber hose him to force him to reveal the crypto-currency was obtained from you
Buying a ranch in the way you suggest to do it would instantly raise suspicions since the fiat amount you are going to pay for the ranch would be substantially below the average market price of similar ranches around there. Otherwise it doesn't make much sense. Further, why would the security agencies want to go after your seller if they could just go after you directly, especially when they see the discrepancy between what you actually paid and real prices?
I guess a ranch in Peru is not something you can easily hide under the mattress
Instead I suggest a plausible different strategy. You treat your crypto-currency as ongoing anonymous investment. You move it around anonymously so it grows gains. From time-to-time, one of the companies you invested in, hires you and converts some crypto-currency to fiat to pay you. You use this fiat to buy real goods
How is that essentially different from your ranch in Peru?