Why do solar terms follow the solar calendar instead of the lunar calendar?

Solar terms refer to the 24 solar terms and climate, which is a supplementary calendar made by China to guide farming in ancient times. Because the lunar calendar in China is a kind of "yin and yang calendar", which is based on the movement of the sun and the moon, it can't fully reflect the solar cycle. But China is an agricultural society, and agriculture needs a strict understanding of the movement of the sun, so farming is entirely based on the sun. Therefore, the "twenty-four solar terms" that reflect the solar cycle alone are added to the calendar as the standard for determining leap months. The Gregorian calendar takes the earth's revolution around the sun as a year, that is, the solar calendar, which is consistent with the standard of the 24 solar terms. The Gregorian calendar only takes the year when Jesus was born as the starting year, and its essence is also the solar calendar.