The only advantages are for criminals as you say, and giving speculators another outlet to speculate on. Those who are worried about currencies losing value and want to protect their wealth would be far better off buying gold (or farmland, or other hard assets) than bitcoin.
If the US government announced tomorrow they would block US financial institutions to from permitting transactions to buy/sell bitcoin, its value would drop through the floor instantly. There's no similar shock that can happen that would cause the price of gold or farmland to drop by 50% overnight.
Its value is mostly being supported by ransomware victims forced to obtain bitcoin to pay off the ransom. No one buys products using bitcoin anymore - there were some articles years ago about random small shops like a bar or whatever that would take bitcoin, but the ridiculously high transaction costs make that a non starter for small items like a pint of beer. Those transaction costs keep rising, in a few more years it would only make sense to buy things on the price level of new cars with bitcoin.
Biting the hand that feeds IT
