My favorite part of Twitter is that it's like a global public email. If you can find someone on it, it's likely you can reach out to them and have a brief conversation in public.

Because the conversation is public rather than private, you can also find existing relevant conversations that might answer your question. No need to always be the one doing the talking.

It can either be someone famous, like John Carmack, Elon Musk, Markus Persson. Or it can be someone obscure, say a person who made your favorite Chrome extension or an indie video game from 2000.

Also, it feels like the place to go if you want to connect with people around a real-time event. Imagine you think you felt an earthquake. You can quickly see if others felt it too.

These are all awesome uses of Twitter that anyone can benefit from without needing to have any followers.

They are also things I would miss if Twitter goes away, because I don't think there's anything equivalent that has these properties (not counting Twitter clones).