Keyboard covers bad for m1 air?

I bought a keyboard cover for my m1 air. Someone told me on here that keyboard covers are bad. Apple support article says avoid palmrest or keycap covers, but I'm unsure of what those are.

The one I have is https://www.amazon.com/gp/product/B0872DKMQ5/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1

it's just a thin film that covers the keys, with a 0.12mm thickness