It's the same elsewhere, be it UK, US or Germany - illegal immigrants rely on cash to survive, as they usually can't just open a bank account with a card. And yeah, some people will always say that it's actually great that illegal immigrants can't access those facilities, after all they are illegal. But I think that's a very cruel view of the world, people in various hardships will always exist and cash is the only fallback that exist if the official banking system rejects you or is inaccessible for you. And it's not just illegal immigrants - people have had their bank accounts closed and placed on some kind of black list by mistake before, how is that going to work if cash is removed entirely? It's already a big problem in most societies, as for instance employers in a lot of places aren't allowed to pay you in cash - so even if you are 100% legit and work a normal job, you suddenly can't be paid legally, even though cash itself still exists and is legal.