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.”