> Often I hear the argument, people saying "I prefer ads that are relevant for me over random ads". But...

You don't even need your "but" (so hold on to it), because this is a classic false dichotomy anyway. Targeting does not require spying nor does spying tend to improve targeting. Basic immediate context (what you're doing, not who you are) works better for both advertisers and willing consumers than personally invasive intrusion does.

You should rather ask whether they prefer relevant ads that put them at risk by aggregating everything about their lives into databases that regularly get breached or relevant ads that don't put them at risk. They can get relevant ads either way. They've just been sold a bill of goods on the need for personal invasion to do it.