Apart from housing the costs aren’t that much more. You pay the same to travel. You pay the same to buy stuff online. Food is maybe slightly more but it’s not that significant.
Once you get past being able to afford housing it’s insanely lucrative. It’s harder for entry level people of course.
Groceries cost anywhere between 25% and 100% more depending on the item (200% more if you shop at Safeway). Gas costs ~50% more. Electric is 200% more unless you live in Santa Clara, in which case it's roughly normal. Water costs more.
All forms of labor cost more (handyman, mechanic, etc). Fast food costs more, normal restaurants cost more.
And that's all before you consider CA sales tax.
But yeah flights are the same so it's basically the same. Sure.
The only thing that's cheaper here than in a flyover state is lemons, as far as I can tell.
Also remember that your net income does not scale proportionally to your gross income. The math still works out, but "rent is more and that's it" doesn't even get close to an accurate picture.
And sure, a Porsche in California costs the same as a Porsche in Kansas, but if you're in "porsche ownership" territory then none of this matters to you, no matter where you live.
I have had that discussion multiple times with people. They all seem to think you absolutely need to live in a 5 bedroom 5m$ house in Palo Alto (because how else are you going to live?).
But if you rent a normal 2BR for 4000$ in the Bay area, and could potentially rent the same for 1500$ in a LCOL, that is a minimal saving compared to your income. Everything else stays mostly the same. An on top of that most companies will give you a paycut.
But for some reason people think you are going to be a king just by moving to LCOL. I think it is the opposite
Now, if you get bamboozled into buying a 5000 sqft house like the average american does, then yes, big savings in a LCOL.