Hello,
From what I read, someone who sells btc sometimes has trouble receiving the fiats in its bank account. If the sum is large, the bank turns on all its red lights. I guess it's not a problem for someone famous, but for an ordinary citizen, how it happens if he lives modestly, recovers his private keys that he lost 10 years ago and finds himself with millions?
The way I see my local investors do it is they move all their bitcoins to the top exchanges because the liquidity on centralized exchanges is huge, and the conversion from bitcoin to USDT is too simple. They then use the exchange's P2P service to convert to fiat little by little, they never place an order too large to make the banks suspicious. I think it is not too difficult to do, converting crypto to fiat is very simple, even if it is millions of dollars.