I love almost every idea I’ve heard that splits up California. But in order to get it so that the majority in the state would vote for its passage, you need to come up with something that the millions of socal folks will go for. They are the majority, they won’t vote for something that makes them give up more than they gain.
Except for Los Angeles County, all socal residents would be part of the new state and free of the political sphere of influence of Los Angeles County. Those socal residents not residing in LA County have much to gain.