The only thing you lose is content, but the same thing is true for web sites that disappear because they have no business model other than making content and displaying it along-side clearly marked advertising - it's not like you or anyone else wants to pay for content.
Well, there is a middle ground - you can enjoy the slow page-loads, bad privacy, and all the other effects of visiting web sites, while also cutting out genuine content, through a second business model: make web sites replace their genuine content with indistinguishable shilling, and suddenly you have the best of both worlds: no clearly-marked advertising; slow page times; and no content!
That's an interesting middle ground.
Edit: got a downvote. In what way does 127.0.0.1 not strictly dominate a web site shilling with no genuine content? It is better in every conceivable way. It's also the future that you asked for, suggesting that web sites come up with a viable business model without any advertising. Or do you just want them to disappear?