Many people have made millions by trading cryptocurrencies, but their first reaction isn't happiness—it's panic, for fear of getting involved in some "source of funds of unknown origin" trouble.

Actually, it's not that exaggerated; most risks don't come from earning the money, but from the process of converting coins into RMB.
When your account is holding USDT, no one will bother you, nor will they casually label you.
The real pitfalls are either rushing to cash out all at once or using unregulated withdrawal channels, accidentally mixing in black money.
It's not hard to secure your gains; keep records of every transaction, clearly track where the funds come from and go to, and make sure the channels you connect with are well-understood.
Don't casually use OTC, especially for large amounts—if the other party's account has issues, you'll be caught in the mess too.
To put it simply, making money is easy, but keeping it is hard; the true experts in the crypto world are not the ones who earn the most in a bull market, but those who can securely hold onto their gains through a bear market.
Always prioritize safety when withdrawing funds; being able to protect your money is more reliable than chasing overly high returns.