I suspect that folk who opted into this would be the ones getting lots of ads (hence the most valuable.)
If Google said "you can opt out for $99 a month" you'd freak out. But you're probably worth that (or more).
People aren't really flocking to ChatGPT though - not yet. Not at Google Scale. It's not like my mom will pay $20 a month when she just uses Google for free...
Plus folk moving now are folk who'll move back later when they get disgruntled there. (No disrespect.) First movers are not the loyal customer base. Movers gotta be moving..
(I say this as a general rule not making an assumption about you personally.)
It's like even everyone "left" Facebook for google+.
Person 2: "Well, they pissed me off so I left completely and now they make nothing off of me."
Person 1: "They already knew you would move so they figured out they would make nothing off of you in the long run!"
Person 2: "..."