I think Google does make money via 9a based on who pays for it. Consumers don't pay for the information. Advertisers do pay for matching their ads to likely buyers.
Key management is how many comply with GDPR today. They encrypt the PII and associate it with the user. Then, when someone requests their info to be "deleted", they zero out the encryption key.
> If you are projecting a receding economy and/or decreased demand for the land you are buying, then it does not make sense to pay as much as you can afford...
I think this is the above commenter's concern; homebuyers are not adequately pricing the risk of rising interest rates. If interest rates go up, demand falls and you're left in a highly leveraged position that amplifies your losses. Monthly mortgage payments don't make the leverage apparent. Sticker price does.
Reification is usually a fallacy when we take the abstraction too far. The canonical example being "the map is not the territory" where someone confuses every mark on a map with actual features of the terrain.
One could argue that abstractions "actually exist literally" without being physical. Gravitational fields don't exist physically but do exist and they're a valid abstraction that's useful to measure. Maybe happiness is a phenomenon that could be useful too (though I would say to a lesser extent.)
A little tangential but... even things that we would say exist physically are not on closer inspection. Does a chair actually exist or is it a platonic ideal that we apply to a collection of atoms assembled to form four legs, seat and a back?