Though would you say that the 'Grauniad' complaints go back far enough in time that at least some of them may have owed partly to conservatives who simply preferred the Times and the Telegraph and turned up their noses at anything northern and pro-Labour? Wiki says the taunt goes back to the 1960s.https://en.wikipedia.org/wiki/The_Guardian
Be that as it may, I really do think the modern Guardian may be trying to save money by using voice recognition software to transcribe stories, and not real human editors. I don't actually read the news page as much any more because it has gotten so sensationalist, but I read the soccer page, and the errors there, and not just typos, can be pretty dire. (The stories are usually interesting, except that they seem to think everyone is interested in English football trivia from years or decades ago.)
Apparently the funding crisis at print newspapers has gotten so bad, with all the revenue from advertising having moved online, that many US newspapers are also using cheap labor in third-world countries (I remember an interview with a writer in the Philippines), and/or computers with machine learning capabilities, to compose short basic factual articles that can almost be written by machines, like wire-service reports of sports events, or local reports like the crime blotter, the city council meetings, the weather, etc.
I was also reading, more recently, that the cultural shift to funding journalism now mainly from sources other than advertising has exacerbated the splitting of readers and viewers into two ever more extremely opposed cultural camps. When TV, newspapers and magazines had to sell advertising that appealed to as many customers as possible, they had to keep their opinions more or less acceptable to a broad middle range. But now that so much online news works on a subscription or donation funding model, sometimes additionally supported by nonprofit foundations, all those funding sources tend to be more partisan, so that 'news' content becomes more partisan and less pragmatic. Both on the right and on the left, actually.
PS re #5: (-: