I think that's fair. Good conversations can and do happen, especially on platforms allowing longer contributions like tumblr, but when a site revolves around following people instead of subjects it makes your interactions a public performance to all of your followers. That has a huge impact on discussion quality, incentivising dramatic takes popular in your corner of the internet and disincentivising saying anything controversial.

When you combine that with poor moderation on most platforms and algorithms that promote outrage-inducing content, toxicity and cancel culture are inevitable imo. It's shit even for creators.