Related, I have been to Slovenia (Lake Bled and Triglav area)

The "Blueberry Snaps" or "Borovničevec" was excellent, and it should be better known. Unfortunately I can't get it here.

They also make variations with Cherries, honey, herbs, just about any fruit or flavour at hand: https://en.wikipedia.org/wiki/Tropinovec

It's a regional thing, as it has a bit in common with Slivovitz (plum brandy from Serbia, Slovenia, Ukraine, Poland and multiple other countries) and Limoncello (lemon-infused liqueur from neighbouring Italy).

I wouldn't just focus on Serbia alone as a unique island of good distilled spirits, that's clearly not the only thing.