Oddly, given the context of this thread, the UK is an exception. Or at least it was until a few years ago (I left in 2019). They have Faster Payments, but they also still use (used?) cheques more often than any other non-US country I've interacted with. For example, a number of UK universities still do (or until recently did?) expense reimbursements in the form of paper cheques, when reimbursing people not employed by the institution. One university even mailed a paper cheque, made out in British pounds and drawn on a UK bank, to our French invited speaker! The speaker found it inconvenient/expensive to have to deal with that, but their bank was fortunately able to figure out how to deposit it.

They are still in use in France from time to time. Typical use cases I have seen are security deposits, and for small non-profits to expense volunteers and getting paid without bothering with payment terminals.

You probably have a very small illegal population, here in the US, if you don’t wanna hand someone a ton of cash but wanna pay them for something and they’re not allowed to open a bank account, a check is the easiest way to give them money. They can go to a check cashing place pay the 1-3% fee and cash the check. Otherwise you’re giving them cash or doing some complicated load to a prepaid card.