"The Left has no choice but to stay on Twitter" can be best understood as the writer saying "I worked very hard to get all my followers on Twitter and I don't want to have to start all over again somewhere else"

We could go on about how we welcome publishers, we don't demote links, we encourage independent developers to build apps and extensions on top of Bluesky's network.... but instead, we'll show you.

All thanks to the incredible community here! 🦋

First post. Looking forward to meeting a new community of people!