Necessary by who's definition? Sure, I like the way adverts allow me not to pay for content directly (or ask people to pay for things I produce directly). That's great. However, some things I value more than that. Misleading advertising is too far, I won't accept it.

If advertising isn't effective enough to be worth doing, fine. We'll find other ways. Yeah, micropayments have never caught on, but maybe there is an alternative, or maybe they won't be so bad once we accept we need a replacement for adverts.

I'm willing to bet non-misleading ads will still be worth enough the whole ecosystem won't collapse.