Han Solo was his breakout role and was at his best in the first film, even if Ford couldn’t have cared less about the science-fiction trappings of the world he was occupying.
Most of what we know about Han Solo when he’s introduced in the Mos Eisley cantina in the 1977 film is established at the end of Solo.
Largely speaking, aside from maybe finding out why Greedo doesn’t like Han that much and watching Han interact with a slightly younger Jabba the Hutt, the Han we know at the end of Solo ought to be the Han we meet in Star Wars.
Ford’s response may have been part of a scripted bit, but it’s awfully easy to imagine that’s his real, genuine answer after spending too much time with Han Solo in his head. How Disinterest Curdled into Disillusionment.
Ford’s disillusionment with Han Solo was perhaps at its peak when Return of the Jedi came out.
As has been discussed in official behind-the-scenes documentaries, Ford thought it was most appropriate for Han to die in a self-sacrificial moment.
The Empire Strikes Back humanizes Han through his star-crossed romance with Leia, whereas Return of the Jedi just turns Han into a caricature of himself.