Maybe if you'd said "Russians" I'd understand, since their banking system is partially cut off, but in that case we'd be talking about money laundering intended to bypass international sanctions.
https://www.swift.com/our-solutions/interfaces-and-integrati...
There’s no separate comms infrastructure for SWIFT, it’s very much vulnerable to internet-based DDoS.
The question then becomes: how is the network designed to handle DDoS attacks? For example, you'd need to identify the network segment or host IP address where the SWIFTnet connections are terminated, among many other things, and I have no idea how you'd do that and if the system builds in resiliency for things like DDoSes.
Of course, the simpler answer is just to blow up the ISPs and cut power to datacenters.
Regardless, if the Ukrainian banking system connection to SWIFT was indeed disrupted, you wouldn't be able to transfer funds to a crypto exchange in the first place, which rather undermines its use as a way to get funds out of the country...
If I were a Ukranian refugee I would be getting every penny I can out into cash, preferably euros. Not sticking all my money into some dodgy internet currency from a country that generally no longer has reliable internet access.
With cryptocurrency, one can transfer and hide one’s life’s savings behind 12-24 words that derive a set of private keys. That is it. Burn it into your long term memory, and you will be able to recover your funds anywhere in the world.
Secondly, if we're thinking about fleeing Ukraine you need to have transfered that money before the crisis. You can transfer a decent amount of money into dollars and be confident it's going to stay stable, you're going to have that amount of cash to leave with. If you transferred into BTC a month ago, you've lost roughly 10% of the money you transfereed just because the volatility. So you're putting this escape money at significant risk (imagine that the war didn't happen, and you've just burned a big chunk of your savings through BTC volatility). Going back to the first point - if you're literally talking about a backpack full, presumably you're talking about sticking your entire life savings into BTC? And just what? Hope it goes up?
Finally, your scheme sounds a little... risky. So Russia invades Ukraine and starts shelling your cities, you've got to travel cross country out of Ukraine, into a Polish refugee centre, possibly facing life threatening conditions. And at the end of it - better have remembered that 24 word pass phrase! Because if you forgot it, your entire escape money is gone forever!
This is something people are doing. It is something directly enabled by this technology.
This goes into some of the uses but doesn't mention atms https://www.vox.com/recode/22955381/russia-ukraine-bitcoin-d...
Personally, if I were living in a place that is at threat of war (and let's face it, this war was no big surprise) I think I'd be much more likely to just keep a few hundred dollars stashed away in cash, than rely on a usb stick.
It’s an issue that regulators like the FCA are keenly aware of, and are pushing banks hard to find a solution to.
For example https://www.hsbc.co.uk/help/money-worries/no-fixed-address/
First, even citizens can find it challenging to join a challenger bank. Some UK citizens don't have the types of documentation those banks require. I once spoke with customer service of one when they asked for a photo of my passport 1 year after I'd opened the account. I knew not everyone had a passport or other document they accepted, and the bank confirmed a substantial minority of UK citizens had no way to meet the identity requirements, and they were fine with not having those people as customers.
So imagine what it's like for a refugee: It is not uncommon to flee somewhere without a passport with you. A bad idea, but obviously it happens. Maybe you never even had a passport.
Second, because the UK "hostile environment" laws exist to prevent access to banking as well as access to tenancies.
In some parts of the UK, banks are required to check your visa status.
If you're a refugee with supporting documents from the UK state, you should be fine getting a bank account, though it may take longer to verify your identity. If you lack those documents, perhaps because you're a new refugee who fled somewhere in haste and hasn't been through the system yet, or whose claim was denied because the UK system is infamously unsympathetic, not so much. Even the online challenger banks will not give you an account until after the visa check.
But then, your point about e.g. tenancy agreement would also get in the way.
In some parts of the UK all potential landlords, even "informal" ones, are required by law to check visa status, and must refuse to give a tenancy to someone who does not pass the checks.