This is just a vibe, so take it for what it's worth.
But personally I feel like I've been experiencing, witnessing, or hearing less stories about people managing to "deprogram"/"convert"/"change" people in terms of their political ideology. Actually I've been hearing more of the opposite, accounts of people regressing: "A year ago I talked my racist uncle into being a Bernie bro but in the last 3 months he's gone all the way back to QAnon." That sort of thing.
It doesn't seem to be just me, I've seen a lot of "Debate Bros" start to have increasingly strict rules about who they debate, or just abandon the whole protect of debating all together to just stream to their existing fans. Some (one in particular 
) openly say it's because they fell like their opponents have consolidated their base and there's nobody reachable anymore.
And that's what it feels like, consolidation. Echo chambers have become more effective, it almost fells like people have scripted retorts to whatever talking point might get thrown at them. Fuck, "Israel" just straight up as academies on how to do this shit. It's like the internet has just perfected rhetoric so much that once you pull someone in they're just locked into it forever.
Idk, I just feel like everyone who is a Chud/turbo-lib/Succ/Tankie RN is probably gonna die one at this point. Every ideology is just a Skinner box now.
Edit: And another thought, it is a bit ironic, I recall us Commies were the first ones to be saying "one-on-one debate is a often worthless performance, and most people who get too deep into Far Right ideology are probably a lost cause and not worth wasting energy to reach," and everyone giving us shit for it and acting all noble about how the market place of ideas could fix everything. Now post-Trump everyone seems to be realizing we were right and Libs and Chuds alike are abandoning the whole affair.
Edit 2: I wrote this while drinking box wine and listening to Post-Punk, sorry. What provoked this was learning that "Why should we bother to reply to Kautsky?" quote by Lenin we all love is probs fake. Made me think about what truth there may be in it even if it isn't actually real.
Edit 3: just woke up and Jesus I made some big ass grammatical errors in this post. Fucking box wine!
If you want a rationalization, I don't see this as meaningful other than the modern social media context rewards dunking on each other more than any other interaction. It is a constant struggle between people who just love the self-validation from upvotes/karma/likes and those that have social anxiety over being wrong on the internet. Therefore coming out and converting often have significant personal cost(relationships/self-esteem) that is very hard to overcome unless you already have a support group.
That doesn't mean people are not moving from one ideology to another or changing their minds, its just that, as you noticed anecdotally people are not sharing that experience anymore.
That uncle probably realized that even though being a sucdem is far better than anything else in the mainstream, it is not "fullfilling" i.e Bernie is completely onboard with Biden and at this point thinking about Bernie/Dems just funnels you into the current blue-red MAGA.
Yes that is a great change from 2016, there are definitely more people that are just some streamer/YTer fanboy with no ideology now. Don't mistake those for real politics imo these people are in it for the parasocial relationship, if said random persona suddenly announced he converted to communism they would bring like half their fans along. But again, don't mistake those for real communists either just because said persona pays lipservice to it. Hasan is a good example.
How many are "socialists" because of Hasan and how many would stay that way if he changed sides? Spoilers I remember he said he would be incredibly more popular if he embraced the right wing grift so there is that anecdote.
I do agree that as a means of actual movement building and social change this environment pretty much destroyed any hopes of a socialist movement. I don't like the same doomer point over and over but at this point our only prospect is balkanization and climate change. I think the way COVID was handled showed all the bad signs leading to towards the bad ending.
I mean, isn't he Cenk Uygur's nephew or some shit? That heel-turn is absolutely in the mail.