I was offered a favourable exchange rate in Bali a few years ago. Handed over £100, and the “officer” at the exchange place counted the equivalent money in front of me. As I reached out for it, he asked whether I wanted an envelope. I said yes, and he took and envelope from a draw beneath the counter, then grabbed the cash he’d placed on the counter and proceeded to place it in the envelope. The cash was out of my sight for around 2 seconds. However, when I counted it later that day, around 20% of it was missing.
I learned a lesson that day.
(Not saying that’s necessarily what those exchange rate places we’re doing in Budapest, though!)
When I was in Poland recently, I didn’t see a single “Kantor” that offered better than the Monzo/Revolut rate. I’d be hightly dubious of those that did.