The left in general is turning into shit tbh and I think a huge amount of it is because of how much of it is online, and specifically anonymous.
A key aspect is how social media is seen simulataneously as a fun activity and as politically educational. People log in wanting to relax, and that is the time they spent reading about politics. This lends itself towards people not wanting to read several articles, or research papers about a given new topic, what they want is funny quips and memes, positivity posts that give a small boost but ultimately give no information. They also dont want to be putting effort into analysing their own position, they want constant reinforcement of it; again in the form of small quotes, and jokes.
Then the anonymity factors in. A huge number of people have no idea who they are getting information from. There is barely any differentiation between people who have been personally affected by said issue, who have been protesting it for 50+ years, and 15 year olds who have never set foot into irl political settings. People can just say whatever they like really and provided it sounds good, it will catch on and be shared by every “activist” online.
So people are so reluctant to engage with anything that makes them think. And of course because of the nature of social media, they can literally filter out any contradictions of their world view; and any and every disagreement feels like a direct attack. And because they are anonymous, and so is the other person, they dont really think of each other like people, and will often say nasty unwarranted shit. This is why my general rule for talking on social media is “If this person sat across a table from me would I say this” and if the answer is no, I dont say it. But so many people are just incapable or unwilling to see a username as equivalent to a face that they will bombard them with insults, send nasty messages, encourage harassment etc. This just creates a hostile culture where disagreeing with someone, even over a stupid niche topic can just get you bullied, which further increases peoples incentive to avoid any interactions that are not simple positive encouragement.