What is the ruling on prostrating on earth and on a mat made of straw, taking into account the preference of the Companions and the Successors to prostrate on earth, and the Maliki school's recommendation to pray on it, and why did the situation change to prostrating on soft carpets?

There is no objection to praying on luxurious or inexpensive carpets. The Prophet, peace and blessings be upon him, prayed on a mat, a khumra (a small prayer mat made of palm fronds), and a rug. This indicates the permissibility of prostrating on a covering or rug that comes between the forehead and the ground. Scholars have unanimously agreed on the permissibility of praying on mats and anything that grows from the earth. The Companions and the Successors also permitted praying on leather and rugs. Although some schools of thought disliked prostrating on rugs except out of necessity, the majority of scholars believe that the matter is broad and there is no objection to it.