Was it plain PLA? Some of the fancier types cause increased wear. I’ve seen photos of glow-in-the-dark filament having worn through someone’s heat block (not just the nozzle). Wood- or metal-filled PLA can also be somewhat abrasive.

Vacuum-sealed PLA can still be soaked with moisture—it depends entirely on how it was handled at the factory. To be absolutely certain, you have to dry it yourself.

The nozzle dragging, though . . . that sounds more like faulty hardware or incorrect software settings—the printer no longer accurately knows where the nozzle is in space. Maybe your printer had a marginal part installed at the factory, and it’s now failed. If so, that’s no fault of yours and you should contact the manufacturer.