Polygamy at least goes back to the Bible and has religious rules around it in several major faiths.
Homosexuality was NEVER seen as equal to male-female marriage, in no major culture in human history.
The Greeks held it as an ideal for male bonding mentor to adolescent student who had to stop when HE became a man. Romans saw men as the penetrators, unless he was an inferior rank or slave. That’s why FU is such an insult, it is both a sexual violation and reduction in status.
The Chinese and Japanese had varying tolerances for homosexual behavior, but they also required the men to have a wife to perpetuate the line.
And in every society that tolerated homosexual behavior with men, women were always treated as inferior. Per Dennis Prager’s brilliant article, it is only when Judaism confined sexuality to the marriage that men started to respect women more, eventually leading to equality for them.
Food for thought.