The web browser and the website are two different piecee of software. Running a web browser doesnt entitle you to access a web server.

You are asking the web server for the page and its giving it to you with ads. If you then decide you dont want the ads the webserver has every right to not serve you the page.

It would be different if it was a local application. Web servers have a material cost for processing a request it costs money to serve you that page. Its completely fair for you to decide that your browser isnt going to display ads but its also just as fair for the website to turn around and reject your request or choose to serve you something else.

Thats fair if you also hold the stance that they can block you if you aren’t paying to use the service. But i doubt you do.