This is your reminder that paperlike screen protectors need to be replaced
I’ve had the same paperlike screen protector on my iPad since 2022. I use it pretty heavily, especially the past year I’ve been writing on it for several hours per day. I could tell that it got pretty smooth, but it happens so gradually that I adjusted to it as it went on. But I finally decided to get the second one that came in the pack I bought, and good lord what a difference. The protector I was using might as well have been the bare iPad screen.
I’ve seen recommendations to swap it every 6-12 months and I don’t know how much it matters at that point, but I can say for sure that 4 years is entirely too long.