"Personal data is one of those things" - disagree.

When people say "Google isn't free, they provide it in exchange for your data" that is precisely saying that there's a market and a trade involved. You may not like that trade, in which case, don't use Google services...

The mere factual existence of a trade/market does not imply governmental or societal acceptance of that market. Going back to the organ example, if you search deep enough you can probably find sites and examples of people willingly trading their own organs for vast amounts of money. Yet that doesn't stop the practice from being illegal, and in most of society's view, reprehensible. Governments exist, in part, for that reason.