What central authority controls Bitcoin?
> Before any crypto transaction who do the buyer and seller both turn to for a "fair market value" ? A centralized exchange.
That's the simplest way today - but definitely not a requirement, and doesn't make it centralized in any way. The centralized exchanges don't set the price (if anything, they suggest it) and they can't control transactions nor wallets. Who doesn't know the private key can't do anything with the funds on a wallet.
> The crypto market is controlled by companies like FTX. This still holds true even if you deal directly with these companies.
The "crypto market" - maybe. But they don't control the cryptocurrencies themselves in any way. This is like saying that because NASDAQ controls the $MSFT market they control Microsoft - of course they don't.