Where is “here”? In the US, for example, defamation is a tort, not a criminal offense. And calling the president or any other public figure a “Nazi” would be totally safe.
The Guardian often reports on similar issues occurring within the UK. Here are just two examples:
https://www.theguardian.com/society/2020/feb/14/transgender-...
https://www.theguardian.com/uk-news/2021/jun/04/gender-criti...
So you are utterly mistaken.
Guardian is as infallible as any other media organisation run by humans who have their own biases.