There’s definitely an argument to be made that they never properly conveyed why people need to see a young Han movie.
Yeah there’s just no real hook. With the main series people are obsessed. With Rogue One people hadn’t ever seen a spin-off (of this kind) before and wanted more OG trilogy stuff. Add to this the production trouble news, the casting of some guy they’re selling as young Harrison Ford. Throw in a release window where it’s competing with a climactic Marvel movie that people are clamouring over and a sequel to Deadpool that many still feel is a fresh idea or whatever and it spells bad news. Personally I don’t think there was enough marketing but I guess they spent so much already it just had to be over and done with.