Ad blockers are a natural evolution in advertising. As they become more common, internet businesses like video bloggers, regular bloggers, and forums will need to adapt the way they bring in revenue. They can implement things like affiliate links or selling your own products; t-shirts, stickers, paid subscription services.
I don't believe there is any use fighting ad blockers or complaining about them, asking people not to use ad blockers isn't any better than begging for donations. I also think this is all for the better, the trend in advertising has been continuously better and better targeting of consumer niches. Advertising is becoming more focused and more tailored to providing information and value before selling a product. Like some of you said, cookie ads aren't always effective, they will offer you products you already have. Advertising is shifting away from that towards feeding people into value driven sales funnels. These are ads that are giving the consumer what they want. On this forum, we need to come up with ways to generate revenue besides browser cookies.
You could have special forum sections for discussion by "premium" paid users, you could have sponsored topics by businesses, the forum could evolve into a media channel where users can get the news and discuss it in the forums. There will have to be new ways to monetize, because the ad blockers aren't going away.