Is it your contention that beliefs about Mary are foolish disputes?
If we are to avoid foolish disputes, we have to acknowledge that what we're disputing is foolish. If it is your contention that arguing over Mary is foolish, okay, we won't argue over her.
An interest in truth is commendable. The Gospels relate several times where the Apostles came to a wrong conclusion or misunderstood what Jesus meant. Such misunderstandings happened before Jesus' time, during Jesus' time, and certainly after Jesus' time.
The reason arguing about Mary is a foolish dispute is because the truth changes nothing about our faith or about what Jesus taught. Jesus taught The Way, and The Way doesn't include living out beliefs about Mary. Such a way of life does not exist. Mary is not a Commandment, a Beatitude, of a Teaching for us to follow, presented in parable form.
Historically and traditionally, Mary has been spoken of as the virgin mother of Christ. Since Biblical times, word/tradition has been she remained a virgin. When did it begin to be questioned? That was in the late second century, not for at least 150 years. Perpetual virginity was confirmed separately by both the Lutheran Church and the Reformed Protestant Faith of Switzerland in the 1500s. It wasn't until the 1800s that mainline Protestant Churches began rejecting the perpetual virginity of Mary. It was the Enlightenment (beginning in the 1700s) and liberal Christian theology that began questioning the perpetual virginity of Mary, which was taken up by mainline Protestant churches.
I don't know when your particular denomination began rejecting early Christian thinking on the perpetual virginity of Mary, or who/what sparked their reasoning. All I can say is that the primary source for the perpetual virginity of Mary were the early Christians, and this appears to have been without question for over 150 years. Church leaders after this (and through the 600s) confirmed this to be the case and it was accepted through the 1500s and the beginnings of the Protestant Reformation. It wasn't until the Enlightenment (1700-1800s) that some Christian Churches accepted Enlightenment/Liberal Theology thinking and began arguing Mary was not a perpetual virgin.
I've often said that primary sources and researching what original authors were saying to their original audience makes a
greater impact on me than what later authors (often over a thousand years later) were saying to their current audiences. This does not make early Christians, original Church teachings, or my own belief/non-belief correct. It merely tells the story why some believe in the perpetual virginity of Mary and why some do not. It also tells when each belief began, and shows which belief date is closest to the primary source, which does matter to some, including some professional historians.
Is it possible the original Christians were wrong? Sure, it is possible. By the same token, is it possible the Enlightenment thinkers were wrong 1700s years later? Sure, that's possible, as well. The bottom line: We don't know, have no way of knowing, and therefore its just a foolish argument as it does not change any of Jesus' teaching and redemption an iota.
All it should do is present to those interested the how, why, when the two different beliefs over the perpetual virginity of Mary came about.