I have "industrial/hotel/motel" grade (short pile) carpet over bare concrete. It's been down for over 20 years and is still "respectable"
Much nicer on the feet than a hard surface. Pins are fairly easy to find on it, too - if one bends over to get them right away!
It will melt if a hot iron gets on it for more than a few seconds. (I don't want to share how I know that!)