This article merges the web with social media too much. I’d argue that Swisher’s letter writing example is similar to someone tapping away at a blog. The broad social platforms and their ethics-absent algorithms are the things that have given extreme positions so much visibility.
Swisher misses a key component. Most advertisers have no interest in being associated with such extreme speech. If the people that advertisers want leave these platforms, the dumpster fire that remains is not a business.