One of the things you find, is that the pattern of courtship has held in pretty much all major civilizations for the last two thousand years. It has been true of the Christian Era, but it was also true (I believe) of Rome in its prime, and Greece. It is true in Islamic countries (many do not know that Islam was originally founded as a sort of reform of Christianity), in India, China and Japan (in their traditional form, before becoming “Westernized). Probably, there have been societies that have not pursued this courtship pattern; and those societies have disappeared. There is little particularly “Christian” about this pattern.
The anthropologist Margaret Mead went in search of a society that practiced some kind of “free love.” This was in 1928 — as “dating” was becoming the norm, and a lot of premarital sex, replacing courtship. She could not find one in the civilized world, and had to venture to the primitive tribes of the Samoan Islands to find an example. People later argued that things were not really so free, even in Samoa, as Mead claimed.
In other words, we have had thousands of years of experimentation with other systems throughout the world, and no other system has risen to the top. You can make the argument that some system will, although today nobody even proposes a “system” at all, but rather seems content with a sort of sexual “Do As Thou Wilt Shall Be The Whole Of The Law.”