Most people aren't given the choice. When they are actually presented an equally simple decision between more privacy and less privacy, nearly everyone chooses privacy.[0] Making privacy just as easy as not-privacy is exactly what needs to happen, and that is likely to only happen through regulation. We can already see how hard companies work to avoid complying with GDPR and the cookie law.
[0] https://www.flurry.com/blog/ios-14-5-opt-in-rate-att-restric...