This is clickbait, there are at least two classes of non opioid painkillers in use since a long time. https://en.wikipedia.org/wiki/Analgesic
I don't feel the title is misleading, but it may be a cultural language difference. The term 'painkiller' is reserved for strong pain relief, and wouldn't include things like ibuprofen. That made me think immediately of a non-opioid pain blocker not just a pain reliever.
Maybe there's some very specific, limited medical context where this is the case but in common parlance it's not at all the case, search for "painkiller" in an online shop like Amazon and you'll find a whole lot of Paracetamol/Tylenol, and various NSAIDs (aspirin/ibuprofen) and manufacturers of those drugs actually use that specific term.