Larry Page (who isn't the CEO of Google btw) still owns all his stock, regardless of whether he's in the USA or the Bahamas.

Larry Page also uses his stock to pay himself.

These cryptocurrencies only have value as long as the market considers them valuable. If Alphabet's stock price dropped, Larry's net worth would decline proportionally.

And yes, they certainly took in money during the initial funding, but Larry and friends did the exact same thing when they pitched Google to early investors.