For me it's always been about control.
If the surveillance companies (Google, Facebook, Twitter, etc.) used opt-in or honoured the Do Not Track header all this could be avoided.
Those that want tracked and targeted ads could request them and those that don't would be left alone.
Instead, by refusing to not honour, Do Not Track or using Dark UX Patterns to make it hard to opt out[1] they're affectively saying, "tough luck, we're going to do whatever we want regardless".
It's a race to the bottom to see which company can get away with being the most obnoxious.
We're left with legal means as the only curbs their behaviour.
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1. Why do so many web sites get away with an "Allow All" but no reliable[2] "Reject All"?
2. Why is there a second set of things to opt out of as "Legitimate Purpose"? Why doesn't the "Reject All", when present, not cover these too?