A spy? a dissident? or something else. If yes then it's recommanded.
If not and you live a normal life I wouldn't recommand it to you. Because you will end up paying more taxes the day they will find about you. And they always catch you.
Privacy isn't the same as tax evasion, privacy means you select who you trust, and exchanges and other companies are known to be untrustworthy with how they handle user data. So, you can totally have privacy and still report your crypto holdings to the government and pay taxes if needed. Of course this is less than ideal because government databases can be hacked too or they can use this data against you in the future, but this is better than being 100% careless about your crypto privacy.