Yeah it’s a good idea if you can afford it and you’re motivated. There are really hardly any public schools in the same league as the top UCs, and pretty much all of them are well ranked nationally. If you look at the private schools that are similarly ranked as Cal and UCLA, the transfer rates are far lower. Your best chance at getting into a great school is transferring into a UC. I moved here to go to community college and I have never regretted it.