Looks like the anti-glare coating is coming off too. That happened to my MacBook and Apple replaced the whole screen for free, that's pretty good considering it was 4 years old.
I ended up rubbing it off. Used a mouthwash for it (alcohol didn't work, perhaps "microcrystals" did the job). If you do that there will be lots of micro scratches on screen, but it's still better than looking at stains, and quite pleasant in dark.
I couldn't get the replacement (didn't know "stain-gate" was a thing).