I agree we need to constantly check our biases . like I said church history is interesting but I do not assume that they knew more then. As a result of leaning on certain dead theologians and assuming they had the corner on truth is a mistake . Augustine, Calvin , Beza , Jacob Arminius , John wesley , Spurgeon ect said some good things ,but also some really heretical things that we need to let go of these ' isms' and use our own sense making .
Certainly theologians have said wrong things, but the point of looking to history is not to find a theological school to subscribe to. it is to find the common threads, the things that haven't changed over time even if they're being expressed differently. If a doctrine is new and different from what the church has historically held, that's a red flag. That's a sign that it is something in the culture sneaking into the church. Is this always the case? No, but not knowing and studying the history of doctrine makes us susceptible to strange myths and foreign beliefs and we must be able to discern the difference.
A perfect example of this is two things that originate with Augustine, the authority of the clergy and the formulation of original sin as total depravity. Both of these things can be shown to originate with him and not be present in the earlier writings of the church, yet because the Latin church did not have access to these earlier writings due to losing contact with the Greek language these things proliferated to the point they are at today.
Yet without understanding of what the antenicean fathers had to say on such issues Scripture itself has been used to substantiate both positions. Some of these views have even become the "natural" reading of Scripture because their view of the verses goes unchallenged by the historic positions since so few read any theology older than 500 years.
It's really not a matter of them necessarily "knowing more" as it is being closer to the original audience. Western readers have gone through at least 4 major worldview position overhauls from philosophers like Plato, Aristotle, Locke, and Descartes that have had tremendous impact on how things are viewed and only a proper appreciation for historical doctrine protects us from novelties and human inventions.