Jim spreads the blame fairly evenly (though I'm sure journos & politicians had more to do with this than Twitter randos), but that just avoids examining the detail, such as what made left-leaning opinion plummet at the end of 2019?
He attributes the overall decline in trust to social media (?), media cuts (??), & criticism of the coverage of Brexit & Corbyn. The Reuters Institute report (reutersinstitute.politics.ox.ac.uk/sites/default/…) is more focused & indicates that Corbyn was a much bigger factor than Brexit: 
In reality, Jim & the Graun hierarchy are sanguine about the decline in trust as the key message (& 2/3rds of this article) is about the paper's growing online reach. In other words, commercial considerations trump liberal angst over the media's declining reputation.
They think they've got a winning formula in the combination of hysterical centrism, haute couture, middle class lifestyle advice, political snark (Hyde & Crace have surely earned pay-rises) & a McCarthyite approach to the dangers of populism. They may well be right.
They are not fussed about alienating leftwing readers because they know online reach means they'll still engage (they understand the social media dynamic), plus there's the ever-reliable nugget of Blairite wisdom: "Where else are they going to go?"
If you want a picture of the future, imagine [the Guardian & the Daily Mail] stamping on a human face— forever.
