One of many reasons why this movie was a bad idea

Not only is the Han Solo character a very iconic character but Harrison Ford is a very iconic actor. No matter who they got to play Young Han Solo it was never going to work out because they would never be able to take any risks with the character or else the fans would be in an uproar so instead they had to make a bland, by the numbers prequel that didn't expand the character or develop him any further. There are several other characters that are also iconic but the actors are not that easily could have worked out, perhaps a Boba Fett movie? Or a movie about how Plageuis mentored Palpatine and Palpatine betrayed him? Or even a Darth Maul movie???

Plus are there really that many instances where an actor takes over an iconic role to play a younger version and actually at least matches the original actor? The only instance that I can think of is Robert De Niro playing a younger version of Vito Corleone and giving just as good of a performance as Marlon Brando.