I don't have much experience with how education works in California, or in the US in general. But there is one universal issue with special programs for gifted kids: parents. It's hard to distinguish gifted kids from average kids with ambitious parents. If you let ambitious parents push their kids to programs they are not qualified for, they can easily ruin the programs for the actual gifted kids.

Gifted programs work best when people don't consider them prestigious or think that they will improve the life outcomes for the participants. When they are more about individual interests than status and objective gains.