You can’t do foreign exchange at a bank or credit union anymore without an account.
You might do better with something FX oriented, but the difference might be small enough to not care.
(Somewhat rant, not really at you, just...What?) It's difficult to believe I'm even reading that. An institution that only deals with currency, and literally has almost no downside to accepting any customer for currency exchange ... won't accept currency exchange?
Most banks have far more resources that an FX stall to verify whether you're handing over junk.
There was a story last month about how banks are the only people left who can even determine whether "fake" Euro coins are fake because they're too high quality "fakes". Counterfeiters are cranking out magnetic, weight matching, material matching, currency that's nearly mint quality. And banks won't even do ForEx? People over in Eastern Europe have just given up. Don't even bother using banks, cause the banks will just tell you all the money's fake.
(TLDR; Feel free to ignore, this entire situation seems idiotic. Like humans just keep rushing towards dumb results.)
So, there are a few things going on. First of all, there are downsides; in particular, it’s a money laundering risk. But also, it’s logistically expensive; the bank has to keep a stock of foreign money, and occupy an actual human dealing with it, and, these days, the rates they can reasonably charge for it are pretty low.
If you’re looking for someone to blame for this, probably primarily blame the free market. Traditionally, banks did physical FX, at rates that were generally a horrendous ripoff, but all consumer FX was a horrendous ripoff so what were you going to do. Today, it’s possible for consumers to do FX with costs in the 0.5% range, lower for large amounts or if they pay upfront for Revolut’s premium plan or something. This doesn’t leave much margin for the banks if they want to be even vaguely competitive, so they’re only going to do it if it’s cheap to do. It is not cheap to do.
This is actually generally a positive outcome for most consumers; FX is much cheaper and more convenient than it used to be for more people; it’s only if you want to exchange physical money that it has become more difficult.