This sounds like a real problem and not just perception. I grabbed a copy from a few years back and compared it side-by-side with a friend's recent one, and the difference is pretty noticeable - the newer cards do feel thinner and more flexible. When I shuffle mine now, I'm way more conscious of not bending them compared to before.
That said, storage might be making it worse for you. Are you keeping them in the original box, or do you have them in sleeves? The way cards are stored really does matter, especially with thinner stock. Humidity and temperature swings can warp them faster too. If you're shuffling them regularly without sleeves and storing them in a regular game box, that's gonna show wear pretty quickly on flimsy cardboard. Worth checking if the creases appeared during play or if they were already there when you opened it. If they came that way from the factory, that's a different complaint than degradation from use.