Interesting. Perhaps that's partially because in the Prequels(Unlike the OT), it's the villains who win at the end of each movie, while the heroes keep losing.
I think that would have been preferred to some as well. Even James Earl Jones famously said about Vader being Luke's father: "He's lying." There might have been the expectation that Vader was lying and that Luke would discover more in from Yoda, only to have them be like "Yeah, we knew. We just didn't want to tell you." Also, that points to the idea that the OT presents flawless characters, which is hardly accurate. Han is cocky and nearly gets himself kiled, Obi-Wan lies to Luke, and Yoda is flat out wrong that Luke would destroy all that his friends had fought for. Really, the only consequence of Luke's decision to leave Dagobah early is that he loses his hand and Vader is his father. The impact on his friends and the Rebellion don't seem all that severe.
The OT did not present flawless characters. But they did prevail in the end. Which is something that I suspect audiences find easier to swallow.
It's mythic storytelling, with classic "Hero's Journey" framework. Not only is it easier to swallow, but for the time, it was unique and dynamic.
Like you said "for the time". But there are other forms of "mythic storytelling". Not all STAR WARS films had to tell the same or similar type of story as the OT.
No, they don't, and the PT was a different type of story as well, and explored different aspects of myth making. The PT introduced stories and ideas that hadn't been explored, as well as different planets, locations and organizations. I just don't think they were done very well from a storytelling and character perspective. YMMV, obviously. As for the ST, I think TFA laid out the groundwork, but the characters are going to go to different places than the OT. So, aside from surface level similarities to ANH, TFA set its characters on a different path.