Maybe the ISP should start charging the ad network instead of the user for ad traffic. Then they can start blocking the ads of people who don't pay. The user, who pays for the service, is getting no value out of the ads and the advertiser is freeloading the ISP's technical infrastructure and userbase.
The internet as you know it is the value you get out of ads. You may hate ads, we all do, but at least recognize the hand that feeds you. The alternative is subscriptions for everything, and as far as I can tell that is far less popular than the ad model we have.
I have no bad conscience whatsoever to use an adblocker. Heck, I get eye cancer every time I have sit in front of somebody's webbrowser who does not have an adblocker installed.
Even though I use the internet quite a bit as we all do, if the free internet were to go away tomorrow, I'd probably find something else to do with my time.