Harrison Ford has wanted out of the 'Star Wars' franchise for a while. It's no secret that even in the original trilogy, he was more than willing to have the character killed off before 'Return of the Jedi'. It is what led to him being frozen in carbonite at the end of 'Empire Strikes Back,' leaving his fate open.
The 'Star Wars' franchise managed to convince him to return for 'The Force Awakens,' where he finally did get that character death he had asked for years ago, but that was not the end. He was brought back yet again as a sort of memory ghost in the recent 'The Rise of Skywalker,' proving that no matter what the circumstances, there is always a way to bring Ford's Han Solo back to the big screen — but there really shouldn't be.
Ford himself is tired of the character. He feels Han Solo's "utility had been exhausted, bled out", and that he was ready to "die for the cause" while speaking on Jimmy Kimmel Live, and he is not wrong.
The window of opportunity to tell a new, compelling story with Ford as Han Solo has long since passed. There has been plenty of time to do a follow up to the original 'Star Wars' trilogy in the years since its release, but the franchise instead went ahead with the less-than-popular prequel series.
When they do, finally, get around to doing a sequel series, Ford's Han Solo is largely there to play up the nostalgia factor and let fans know that the movie would be playing it as safe as was possible. He was inserted into the movie as a way of luring fans by way of reassurance, in a way for the film to say: "Look. It's still the 'Star Wars' you know and love."
It had been at least 30 years since fans had seen those characters, but really, nothing had changed in any significant way.
Han and Chewie were still rogues, traipsing across the galaxy and getting into trouble with criminal elements. Han had not really done anything with his life beyond fathering Ben Solo (Adam Driver), and even that story arc was more about Ben than about Han. The sequel series had a chance to do something new with the character, but it's not a direction they chose to go with. It's definitely too late now. Not because Han is dead — there are no limits to the ways the franchise can bring him back — but because his story arc is.
Han's role has been reduced to that of a 'Star Wars' mascot, and each time 'Star Wars' brings him back, it shows that they have no real plan for their story beyond trying to make people feel good about better stories long past. Every time he is brought back, any character depth he had matters less, and less. With the Skywalker Saga finally coming to a close, 'Star Wars' is in a place to look to new stories that can stand on their own without the long shadow of the original trilogy hanging over them.
Retiring Han Solo once and for all is what the franchise needs. It's what fans of Han Solo at his best deserve. Most importantly, it's what Ford himself wants. He doesn't need another film appearance to know just how much he's meant to the 'Star Wars' fandom — he knows.