Traditionally fireplaces have been built of stone. They last longest under extreme heat conditions. Sooner than later the design was elevated and carvings were employed. Then it was not only their warmth, which made them the focal point of a home.
During the last few centuries many different fireplace styles and variations have developed. What has not changed is the desire of the owner to express themselves and display their status.
Such expressions focus mostly on the main living room fireplace. Other rooms, such as kitchens, bedrooms, even bathrooms are usually much simpler in design. Unless, of course, you look at a castle.