Thank you for your graciousness.
Perhaps various Protestants may agree with Catholics on more things than they realize, as well as the fact that they misunderstand various doctrines.
Depending on which Church Fathers they are quoting, you could also say that makes them closer to Orthodox.
The evolution and comparison of theology is a fascinating and also vast volume of information. I've been working on assimilating and understanding it for a few years. I've added to my own knowledge, but I doubt my lifetime will be sufficient to fully understand.
Btw, if you are interested in such (not quite sure if you are?), Fr. Andrew Stephen Damick's Orthodoxy and Heterodoxy is a good overview. He basically compares and contrasts everything else with the Orthodox Church, but because of the order, a lot of the process of theological development can be seen. He's not always gentle, though - very straightforward, but not terribly diplomatic. He does at times praise the truth found in various denominations, and pretty much lays it all out, from an Orthodox point of view.
Personally, I tend to view Catholics, Orthodox, and Protestants rather like a Venn diagram of three circles arranged like the points of a triangle. There are overlaps between all three - much of the core of Christianity. And because the Catholics shared 1000 years of history with the Orthodox, we have much in common. But we also have 1000 years of separation, resulting in teaching within Catholicism that Orthodox do not share. Then we have the Reformation, when the new Protestants rejected what they saw as Catholic errors, but obviously kept much of the faith as well, resulting in an overlap between Catholic and Protestant, but also uniquely Protestant doctrines. From the Orthodox point of view, they correctly identified some things as error, which gave them overlap and moved them closer to Orthodoxy on some doctrines. But some things they rejected but should not have, and other things they created wrongly (from our point of view), creating uniquely Protestant doctrines that overlap neither Catholic nor Orthodox.
What happened in the following centuries, though, is tremendously complex and varied. So my characterization of "Protestantism" here is not exactly accurate, because it has and continues to change.
That's my little theory and way of understanding it anyway.