Real reason: The Guardian can't handle when readers community note them using.. The Guardian.
https://twitter.com/MarioNawfal/status/1821189070401249385/p...
This. It's not just The Guardian, though. It's pretty much all moss media. They got too used to an era where they could talk and the public couldn't talk back (or they could but only through letters to the editor which they could conveniently filter to just the voices they wanted to hear).
To be fair, Social Media is just like the "Letters to the Editor" section, except the social media company is the publisher and is the one doing the filtering.