Unless you run an ad-blocker, which makes browsing the web painless. But then some would make you feel guilty for "stealing" free web content. But is it really stealing?
No. Why? Because this is the open web. The purpose of the web is that you, the user, get to consume content in any way you want, and if the creators didn't want that, they have alternatives.
Free content is a choice
Making content freely available is a strategic choice by the creator. Using advertisements for monetization is another strategic choice. In the former case, the user gains value, while in the latter, the user experience is degraded. Neither are strictly necessary.
Some creators choose alternative business models that either do not include free content or do not include traditional advertising. Two case studies:
1) DaringFireball.net: blog of John Gruber, a popular and snarky Apple pundit. His site is successful and influential, and has no ads. He does sell sponsorships, which appear as native posts on his page and in his feed.
2) Stratechery.com: deep tech business analysis by Ben Thompson. He offers a combination of free weekly articles and a paid subscription for additional daily writing.
These are two examples in a large field of possibilities. Free content with ads is not the only possible business model.
Turnabout is fair play
There are multiple ways to detect and block users that have ad-blockers. Creators have had the option to thwart ad-blockers since the first Firefox plugins became available. The majority choose not to block the blockers as a strategy, because the loss of those users would be a greater blow overall, and blocking the blockers is seen as an aggressive stance by many users.
That being said, the creators are free to either block the blockers or serve alternative content to them, but they choose not to.
Ad networks and privacy
The greater issue for many users, myself included, is tracking. Most ads come from a small number of ad networks which are present on many different sites. These networks track your usage, so that if you are looking at a product on one site, you'll see advertisements for that sort of product on many other sites across the web.
The ad networks track users invisibly and without the user's consent. The content producers argue for the legitimacy of this tracking, because it is part of the implicit contract between a site creator and its users. That's a load of crap. The common user doesn't have the technical education to understand what's happening behind the scenes. And even if they are sophisticated enough to block third-party cookies, that doesn't prevent browser fingerprinting, Flash-based super-cookies, use of the new HTML local storage API, etc., which are all much more sophisticated, complex, and hard to prevent.
The way the open web is supposed to work
This is going to get a bit technical; I want to explore the role of the web browser with respect to content on the web.
The client which initiates a request. These are often browsers, editors, spiders (web-traversing robots), or other end user tools.
The CSS 2.1 specification's definition is similarly open:
A user agent is any program that interprets a document written in the document language and applies associated style sheets according to the terms of this specification. A user agent may display a document, read it aloud, cause it to be printed, convert it to another format, etc.
Some user agents aren't capable of viewing modern ads. If a user of
NCSA Mosaic browsed a site containing HTML5 banner ads in an
browser does not support any of the technology mentioned. It would likely render
the content from many sites, but it would fail at serving ads.
Again, from the CSS 2.1 specification:
The inability of a user agent to implement part of this specification due to the limitations of a particular device (e.g., a user agent cannot render colors on a monochrome monitor or page) does not imply non-conformance.
UAs must allow users to specify a file that contains the user style sheet. UAs that run on devices without any means of writing or specifying files are exempted from this requirement.
The user agent MUST provide ways for users to override the entirety of the styles on a web site! That is necessary for standards compliance! This puts an onus on the users' ability to choose which content to display and how.
The user chooses a user agent to decide on his behalf what content and functionality he wishes to prioritize. This could be a browser with an ad-blocker, a read-later application, a text-based web browser, an RSS reader that supports "mobilization" of content, or any number of other configurations. These are all fine. You don't need "adblock absolution." If a creator puts his work on the open web, making no effort to restrict consumption, you are under no obligation to view the ads on the site, submit to invisible tracking, or consume the content under any condition other than your own. Conversely, the creator is free to block ad-blockers, put content behind a paywall, ask users for donations, etc.
The popup blocker did not doom commercial web ventures. Advertisers moved on to ads that users found less objectionable. which adblockers (currently) can't target Certain classes of ads, such as sponsorships and native advertising, These are less obnoxious, and some studies say are more effective.
Finally, without the freedom to modify the way web content gets displayed on your browser, the world would never have the best browser plugin ever: Cloud to Butt Plus.