The Guardian is a pretty terrible choice for people who want less opinions mixed in with their news. Their front page with all opinion stuff removed would have a lot of blank space. Not only is your statement about proper labelling false (random recent example: [1]), but on top of that they seem to think that their own opinion entitle them to their own facts. A non-political example: they accused in passing the journalist Matt Taibbi of rape. When confronted with the debunked claim [2] the Guardian contributor's response was, essentially, "it wasn't news, it was opinion" (does that remind you of some cable news channel?). For context TG is not some 4-person blog with no fact-checker, they are a 1400 employees company, and yet somehow these "mistakes" happen.
[1] https://www.theguardian.com/culture/2019/jan/19/is-standup-c...
[2] https://www.pastemagazine.com/articles/2017/12/the-destructi...