For Liu Bei, Kuang Han is a banner of justice. It is precisely because of this banner that Liu Bei can get the respect of Cao Cao, Yuan Shao, Liu Biao and others (at least on the surface) after constant failures and rebellions. In fact, Liu Bei and Lu Bu were similar at first, but why are their images so different? I'm afraid that's the reason.
Have you ever seen Yi Zhongtian taste the Three Kingdoms? It is said that Liu Bei threw away the flag after he proclaimed himself emperor, otherwise Guan Yu would not turn against Wu after his death. It is also said that Zhuge Liang received the flag after Liu Bei's death, otherwise he would not have left Qishan. Does Zhuge Liang want to revive the Han Dynasty? No one knows. I'm afraid it's just for making contributions. Of course, Zhuge Liang is already great. If he reunites the three countries with his ability, I am afraid it is unprecedented.
History is hard to say. If you want to have fun, just watch the romance of the Three Kingdoms, regardless of his purpose.