Before central heating, carpet was a good insulator and added to the warmth of a home during the cold seasons.
A beautiful area rug can also greatly enhance a rooms decor.
But - there really is no good reason (that I can think of) to have a carpet on your sewing room floor - unless your home is on a slab foundation. Then a carpet can make a real difference in how warm your feet stay on a cold day.
That's my situation. I've been thinking about going to Lowes or Home Depot to get an inexpensive piece of vinyl flooring to put over it! The reason I haven't done it is that it might create a falling hazard.