I lived in the UK for over a decade and read The Guardian for most of it, as well as for a few years after leaving.

For starters, they see themselves as Opinion Makers, not Journalists.

Then almost all of their journalists and columnists are scions of the British upper middle class people who frequented expensive private schools as kids (which, curiously, in the UK are called “public schools”) something which only about 11% of children in Britain do. This gets reflected in the takes they have, some of which are ridiculous - like the regular columnist Identity Warrior Feminist who wrote an article about the evils of “men who use sex dolls” (I! Kid! You! Not!) with not even the least bit of awareness that it was the same kind of thing and in the same style as decades ago was written against the “perversion” of homosexuality - a fashionable rich girl “Identity Politics” take rather than the “people should be free to do what they want with with their bodies” principled take, hence we get moralist articles in the same style as used to be done against homosexuals but since they’re against targets which are not part of the “groups it looks bad to criticize nowadays” they get written and published there as if they’re Progressive when in fact being Regressive.

The Guardian are mainly the voice of the British Upper Middle Class, so strongly Neoliberal and not at all concerned with things like Equality or Social Mobility unless it’s for the upper middle class (for example, they do care about the “glass ceiling” stopping upper middle class women with a priviledged “public school” education from becoming extremelly well paid CEOs, but they don’t care about the rest of society not having a chance in hell of getting anywhere near that).

It’s thus not suprising that they spent more than a year spreading pro-Israel messaging during the Gaza Genocide, which means things like quoting what the IDF said as fact, and still today use differently charged language depending on the side (for example Palestinians “die”, Israelis “are killed”).

They also gleefully participated in the slander campaign against the last leader of the Labour party some years ago to get him out - to be replaced by the guy that’s currently getting old ladies arrested as “terrorists” for demonstrating against the Genocide - which was done in cooperation with Israel-aligned Jewish groups in Britain and involved accusing him and the party under his leadership of anti-semitism, which was so extreme that at one point a Jewish Holocausts Survivor was deemed an anti-semite to try and get to that Labour Party leader by association (they sat together in a panel in a conference for Palestine).

Even further back, I remember how they strongly supported British participation in Bush’s (Junior) invasion of Iraq “because WMDs”.

Oh, and they also do the same shit as in America (but not done in most of Europe) of explicitly chosing and supporting a political side in elections.

They’re basically a Neoliberal propaganda outlet, out to convince people to side with certain ideologies and certain political and economic interests, only “good” if in comparation to the rest of the British Press because the Press environment over there is trully horrible (the least trusted in Europe, according to a poll some years ago).

Then of course, like almost all of the British press they have this heavy nationalistic Great Britain is Great and Wise, Foreigners Are Not - basically, Brits always know better than anybody else, foreigners are inept an incompetent and everybody looks up to Brits or should - take on pretty much everything international.

In summary, they’re not there to inform, they’re there to convince, don’t actually have Journalistic Integrity and pretty much always take sides, especially when it comes to British internal politics.

That said, IMHO they have exactly two columnists who are honest and left of center: George Monbiot and Owen Jones, plus Ben Jenning’s cartoons don’t pull any punches.

Also their coverage of the US is in general sorta independent (still slanted on the neoliberal side) mainly because except for the one or two columnists who do live in the US, they’re basically outsiders looking in and don’t really have a stake on certain outcomes or supporting certain factions there so are far less likely to pussyfoot around criticizing one political side or the other.