Rather than sidestepping the law, you can be sidestepping official corruption or crime. There are lots of cases where people who are supposed to be enforcing the law instead use their law-enforcement powers for their own benefit, sometimes in ways that are illegal, officially speaking, but in an unenforced way.

It's perfectly legal for me to, for example, donate money to WikiLeaks. But Visa and Mastercard aggressively canceled every merchant account that allowed people to donate to WikiLeaks through the Visa and Mastercard systems, apparently because of secret pressure from US government officials who were unhappy about some of the things that WikiLeaks revealed. The Snowden revelations — which may not have been legal, so they are peripheral to your question — very likely wouldn't have happened without WikiLeaks being able to support him, which they could only do because they could receive Bitcoin.

Similarly, many Patreon accounts are getting canceled because their owners have published things that are embarrassing to Patreon, but not illegal (typically, racist remarks). If Bitcoin becomes mainstream, there won't be a centralized authority like Patreon that is in a position to end people's livelihoods because they publish politically undesirable viewpoints. (Right now, those viewpoints are viewpoints that are odious to you, but there's no guarantee that that will be the case in the future; it's easy to imagine Patreon bending to Chinese government pressure to censor people who talk about Falun Dafa persecution or Tiananmen Square, for example, even in countries where that is legal.)

As another example, many Venezuelans are having difficulty fleeing the country, even though fleeing the country is technically legal, due to both official corruption and armed gangs. You could argue that it's not clear what is and isn't legal in Venezuela right now because there are two competing governments, but neither of those governments authorizes demanding bribes from would-be émigrés.

As yet another example, it's perfectly legal in Iran and France for French companies to do business with Iranian companies. But, because much of the world financial system is controlled by the US, it can be difficult in practice; see https://www.washingtonpost.com/world/europe/europe-says-it-w... for more details. Regardless of whether US law is misguided or not, under well-established principles of international law dating back to the Peace of Westphalia, it certainly does not apply to French companies doing business in France with Iranian companies in Iran.

So, in a sense, I think you're right that the main purpose of cryptocurrencies is to sidestep violent coercion. I think you're terribly naïve about how much illegal violent coercion is actually "the law", although that's understandable if you've never lived outside a developed country.

There are other uses as well; it's a dramatically better way to send money overseas, for example. Last time someone sent me money via Western Union, I had to go to three different locations, stand in line for twenty minutes, hand over a massive amount of personal information (perfectly suited for identity fraud or targeted home robbery) to an unaccountable third party, sign a false statement, and walk out the door into a dangerous neighborhood with a pocket full of small bills. For this "service", WU charged me/them about 10% of the money sent, and also didn't inform me when it arrived. Bitcoin transactions require none of this nonsense and cost much less; the last Bitcoin payment I received from overseas cost 0.3%, and I received a notification in a few minutes in my Bitcoin client of the transaction.