No.. many cents of it are withheld, by law.
Elon uses his vast wealth to influence, intimidate, and generally get away with lawlessness. He effectively took huge loans from banks to buy a giant bullhorn in Twitter. Those loans are collaterized by unrealized capital gains. And more generally, billionaires have the ear of politicians because of what they could do with their money. So you don't need to realize gains (gains which are taxed at a more or less flat rate!) to make use of your wealth.
Though like I said, Larry is not really a bad guy in the world of billionaires. I would only support taxing him more than I would support levying additional taxes on w2 income assuming CA actually had a provable need for more money. (Right now I think they waste most of the budget.)