(Disclosure: I used to work at the Guardian, a million years ago, and helped with their early entry onto the web, including decisions about not having a paywall.)

What the Guardian has, throughout its editorial, is a political position. This is something that UK national newspapers naturally evolved over time as a differentiator, and is common (but not universal) in many countries. There are various political stable-ish ecological niches -- left, center-left, center-right, upper class, business, popularist right, and various news media that have staked out their territory. That means that they can attract with "ragebait", and also build a reasonably consistent (or self-consistent, at least) factual reportage. Someone who leans right-wing but wishes to be informed might buy the Guardian regardless, because they can disregard and triangulate. You have a core audience, and as long as that audience is loyal -- and needs some connection to reality, you can fund greater than just ragebait.

Ragebait isn't the only business model for supporting honest journalism, and one of the lessons I learned at the Guardian is that the actual business models can be surprising and frequently unrelated to news reporting. For many years, the Guardian was kept solvent through used car sales via Autocar, the most profitable asset in the Scott Trust. (One of the reasons why the Guardian was so early going online is that its editors, in particular Alan Rusbridger, recognised presciently that the Web was going to absolutely gut Autocar's profits, and so they needed to get ahead of the game.) You will be surprised about how many booms and busts in UK media industry have been determined by audience-pullers like crosswords, bingo, photos of naked models, and sudoku.