In all the years of using one I never thought it made anything sacred. It keeps my forehead clean and cushions my knees

This reminds me of the practice in Egypt where men would intentionally press their heads into the ground when praying in order to develop a callous, colloquially called a zebiba, showing off their piety. Is this still fashionable? When I traveled rural Egypt in 2008 it was omnipresent; one shopkeeper told me he no longer believed in religion, but he had to develop a zebiba nevertheless, otherwise no one would buy from his shop.

(I'm a Muslim). I mean... Strictly speaking as far as i am aware the mat/rug is not sacred itself. It is just a place to put your head +knees comfortably.

In fact the Prophet Muhammad SAW did not use a prayer mat and instead he placed his head on the soil (ground/earth).

Also note; Shias place their head on a stone/rock to mimic this practice: https://en.m.wikipedia.org/wiki/Turbah