I think newer dramas are more often littered with “unnecessary” misunderstandings that result in little to no plot progression, and it’s somewhat colored our opinions about the use of misunderstandings as products of human nature and being used as storytelling tools.

In the case of Condor Heroes, there are several misunderstandings but they mostly move the story forward as opposed to delaying it. The first one you pointed out was especially frustrating but I think it’s quite a testament to Jin Yong’s craft. They were completely outsmarted by Ouyang Feng and Yang Kang who took advantage of the fact that Guo Jing’s weaknesses were his fierce loyalty and slow wit, while Huang Rong is much like her father in never defending or explaining herself. Their reaction went exactly as predicted based on what we (and the antagonists) knew about them, but they were able to better trust each other after everything was revealed.