@HilliTech I have a lot of thoughts about this particular subject.
I was one of the migration events. I came in a lot slower than others and I adapted, I think, readily into the flows. Just giving you the details so you can see through my eyes.
I had so many people explain how hard, technical, and impossible it was to even sort out the concept of Mastodon. The majority of those people were very active on Twitter, saw what was happening and have desperately clung to their audiences, or tried to find purchase on all the sites all while screaming how hard things are.
As you said, it's no more difficult than signing up to a million other things people do all the time. The only difference is the gap they have in people "moving their cheese".
Sure, there are some struggles to learn the new environment. But people are competent. Overall - people are entirely capable of growing into areas they want to. If they want it.
I don't think people want it. Most people, don't really want to change anything. We are creatures of habit and like to do things that we understand. Bird site is so synonymous that it is basically assumed you have a massive followership if you're a company or even real. People learned that THAT, the large followership, was somehow the measure of success.
They don't want to try it over here. It's risky having to pivot your business model. Or your engagement model... or your entire product model. For some people, posting to twitter is literally all three.
It's hard to convince someone of something they are paid not to understand. Twitter feeds them - until it stops, they'll resist admitting it's over.