MacBook Air M1 Screen Stains: Should I Use a Protector?

Hi everyone.

I'm worried about something similar to smudges on the screen of the MacBook Air M1 (purchased in March 2022). I've tried to remove it with a soft microfiber cloth many times without success.

Searching about it, I found a user who had exactly the same problem as me from the screenshots.

Macbook Air M1 Small Black Dots On Screen… - Apple Community

Is this a known issue?

I would like to know the cause, I doubt that a grain of dust can cause this damage, could it?

Is it advisable to use a screen protector for this MacBook?

Macbook Air M1 Small Black Dots On Screen… - Apple Community

Photographies (with all white screen):

(I've had no other problems with the screen.)

Thanks in advance!