Obviously, a problem not even fully addressed by L2’s datasets. Sure, but the use of proxies to masquerade the identity of users being sold to researcher buyers that paid for a different service is fraud
Users/respondents lie, and many buyers/researchers are neo-luddites; most C level still come from the telemarketing days. A fun example: mobile targeting is terrible when off wifi because all survey platforms uniq identify users based off their IPv4, so any T-Mobile LTE users in the same city going through the same CGNAT often share profiling data that ends up conflicting, which ends up meaning they don't get sent into the best survey(s). The issue is even worse in heavy IPv6 countries like India+France.
Yes. Much better to leave these decisions to the Dear Leader who is infinitely wise and cannot be misled. Or to the People's Central Planning Committee, where they decide all the allocations and strip rich people's wealth if they aren't on board with the correct ideology. Such systems are non-broken and have yielded unmeasurable prosperity throughout the world wherever implemented.