That's not really true

It is absolutely true. The fifth amendment means US citizens have a right to silence. It has already been ruled that neither the government nor the courts can compel someone to divulge a password under those fifth amendment protections, which is why former mayor Eric Adams was able to avoid having his phone searched by the FBI.

Whether this is destruction of evidence or not will be a decision made by the courts (it's a question at the heart of the matter in the first place), and the facts that he was allegedly repeatedly denied access to a lawyer and not read his Miranda rights are both things that are decidedly in his favor for getting the case tossed before that question is even addressed.