Not sure I get it. Will have to give it a listen. I can't wrap my head around how a UI can ignite toxicity. It can encourage toxic behavior to some small degree. But mostly, the incentives awarded for that kind of content push it further.
One thing that comes to my mind is that Twitter content is presented very densely. It may feel a bit claustrophobic? And we know that fear pulls the worst out of people. This may be a psychological trick, like having no windows in stores, casinos, etc. That's why I like nostr:npub1pu3vqm4vzqpxsnhuc684dp2qaq6z69sf65yte4p39spcucv5lzmqswtfch; it doesn't cram that much content on a screen, and thus it feels a lot more relaxed.