Let's compare it to the situations Ukrainians found themselves in.
They needed to flee the country, but there was a chance border guards would steal their money if they found them carrying a lot. The same would happen if they were found carrying a bag of gold.
If they happened to enter the EU, they wouldn't be able to fly anywhere because you cannot carry a lot of cash and valuables like gold, jewelry, including watches, and cash. AFAIK the legal limit is somewhere around 20k EUR. So, in a situation where you have to migrate with a lot of money, bitcoin is the obvious choice.
If I remember correctly, in the European Union you can travel with up to 10k euro without declaring the money; if you have more than 10k euro with you, you can still travel but you are require to declare the money, if you don't and they discover you, the money will probably be confiscated until when your position is clarified. I think in the USA is pretty much the same but instead of 10k euro is $10k. But as I previously said, we're talking about declaring the money, not as a maximum limit you are allowed to bring with you.