pretty sure a sad fact about getting older is that our ability to taste sour things starts degrading, but I've definitely had bags that had barely any sugar on them too
(also some where for some reason they were damn near rock hard, despite not being anywhere near the sell by date, but who knows what's behind that one)
I normally don't bother with like Trolli or any of that. It's going to sound wild but the dollar store ones have been hitting my sour cravings pretty well.