Where the premium price ends up in the print quality varies. Sometimes it's ease of printing, sometimes it's thermal properties for better printing, sometimes it's higher dimensional accuracy, sometimes it's color vibrance, sometimes it's tensile strength, sometimes it's additives for heat or uv resistance, maybe elasticity, longer shelf life, better bed adhesion, etc.

Sometimes it's nothing and you pay more for no tangible benefit. Sometimes you pay more for brand names or environmental impact implications.

Premium price does not just linearly translate to better or easier printing. A lot of it comes down to poor storage conditions, preparation, printer maintenance or operator error. The practical difference between the cheap stuff and the stuff that costs twice as much is more in company profit margins than anything we see. People just fool themselves with anecdotal confirmation bias and brand loyalty.