Yes in the old testament polygamy was accepted because many followers of God married multiple wives. People like Abraham, Solomon and David married more than one wife and they are all strong men of God who teaches people to follow God. However, these situations often came with conflict, jealousy, and family struggles, suggesting that while God permitted it at certain times, it was not His perfect design for marriage.
But from the begining of this world, God have made it to be one man and one wife. In Genesis, a man is described as leaving his parents and becoming one flesh with his wife, which points to a singular, committed relationship. This standard is reinforced in the teachings of Jesus, who emphasized faithfulness and unity in marriage rather than multiple partners.
We all know that in the new testament, the idea of marriage changed during the times of Jesus Christ where we are instructed to marry only one wife so as to promote monogamy. While God may have allowed polygamy in earlier times due to human circumstances, the overall biblical direction points toward one man and one woman as the model that reflects God’s intention for marriage.