I know we’ve covered this in triplicate, but by this logic Ep 4 may as well have been called ‘A New Hope Among Many’. The whole point of the OT is that Luke is unique - that he’s tapping into something rare and difficult and mostly forgotten. Why else would the series be so invested in him personally? When Obi Wan solemnly declared “That boy is our last hope”, why didn’t Yoda simply say “No, any idiot will do. Let’s get that Solo guy. He seems confident”?
Or he was the last hope because of his family connection to Vader (“the other” was always meant to be his sister, too, even when that sister wasn’t Leia).
I think Obi-Wan and Yoda believed that being forced to confront his offspring would put him off balance enough to give Luke an edge. It turned out that they were right to place their trust in Luke, but not for the reason they believed - it was because Luke didn’t lose faith that his father could be saved.
It wasn’t because they simply couldn’t find someone else who was strong in the Force to train.
And if you’re going by prequel “rules,” they (or at least Obi-Wan) believed that Luke - or at least, one of Anakin’s children - was the Chosen One, rather than Anakin himself as they’d all believed before. So, by buying into the prophecy, yeah, he would’ve seen Luke as the “last hope.”
It’s hard to know where to draw those familial lines given that Vader wasn’t even Luke’s dad when Obi first posed the notion of Luke learning the Force - nor was there any ‘20 year plan’ on behalf of Obi Wan and Yoda. When the ‘other’ was initially presented in TESB, she was supposed to be someone who had been trained on the other side of the galaxy - the operative word being ‘trained’. It was only to dig himself out of a story hole that Lucas made Leia the sister and planted the idea that Skywalkers were a worthy threat to Palpatine based on heritage/genetics alone (cue Midichlorians). As far as Luke being any kind of ‘hope’ via the unanticipated (by Yoda and Obi Wan) redemption of Anakin - well I’ve made a lot of noise on these threads about how I feel Luke’s role in RoTJ was completely and utterly redundant with regard to that final battle.
Look, the whole Force thing is as elastic as anyone wants it to be. I just think the reason so many fans are up in arms about Rey’s instant and consequence-free power levels is that the previous films greatly imply a deep and difficult learning curve with regards to the Force. Also, the OT has the Force (and Jedi) as something forgotten and elusive and even snickered at. If Force-powers really did pop up everywhere like the ST implies, surely someone like Vader wouldn’t have wielded the terrifying influence he did in TESB. Wouldn’t there be a reasonable number of Imperial officers who just happened to be pretty good at levitation or Force-choking (perhaps they saw Vader do it and learned it instantly like Rey did) that could defy Lord Vader’s many homicidal tantrums? No, Vader was the last personification of a forgotten art. It’s not like Admiral Ozzel could turn to his fellow officers and say “look, don’t worry about Vader. My kid Force-choked his teacher the other day. Anyone can do this s##t”.
Making the Force - which is/was the spiritual backbone of the series - something easily dealt with and more or less unlimited diminishes it and, by extension, Luke Skywalker’s journey.