Why do most of the replacement shoes have their toes upturned?

Why do most of the replacement shoes have their toes upturned?
This is not only a question in China, but also in the field of shoe culture in the world, because Chinese and foreign ancient shoes have a history of more than a thousand years. The national shoe wares study its style and regulations, and we can generally get the answers to the following four causes:
First, both men and women in ancient China used skirts and gowns as the main body, and the shoes can be used to support the hem of the skirt so as not to slip.
Second, the shoes are warped when walking, which has a warning effect and protects the wearer from harm.
Third, the shoe warp is generally connected to the sole, and the fastness of the sole is much better than that of the upper, which can prolong the life of the shoe decoration.
(The above three points are the laws explored by the ancients in long-term practice, which have certain practical value and scientific nature.)
The fourth point is a strong sense of feudal superstition. The upturning of the toe of the shoe seems to have the same explanation as the upturning of the top corner of the ancient building, which is the result of belief and respect for heaven.