Basically, Mastodon still can't explain in layman's terms how users should think about its federated model, or why they should care. This 30% bump is driven entirely by short-term drama around Twitter. I bet you that in the next few months, you will see Mastodon's DAU's drop back to around what it was before this whole mess.

The biggest reason for this is that, as you yourself said, Twitter's UX is terrible but Mastodon is almost identical. So why switch?