Because the revenue from a user who blocks ads doesn't stay at 100% of the current levels - it drops to *zero*, *forever* (no user ever googles "how do I stop blocking ads?").
The majority of web users are running an ad-blocker:
https://doc.searls.com/2023/11/11/how-is-the-worlds-biggest-boycott-doing/
Web operators made them an offer ("free website in exchange for unlimited surveillance and unfettered intrusions") and they made a counteroffer ("how about 'nah'?"):
https://www.eff.org/deeplinks/2019/07/adblocking-how-about-nah
16