Twitter is where they get the engagement. Many of them have or have had a presence on other platforms, and some send out newsletters and so on, but engagement comes from Twitter. Their readers are there, the people who buy their jewelry and art, support their fundraisers, etc.

I've seen already that not everybody I want to keep track of from Twitter is going to the same place. There won't be the same concentration of people in any one place. Also, the other platforms that people are already getting accounts on just in case aren't equipped for the influx. They might grow eventually, but the gap in time is going to be very bad for artists and publications that are making it now, but not by much.

P.