All it needs to do is to get rid of the invite system (early) and open up its web app [1] and you will just watch it grow faster than the rest of the alternatives, and over time Twitter users will naturally move to BlueSky.
What they got right is that they have both iOS and Android apps early and there is no 'choose an instance' mess, with proper search functionality and there's a official default server to avoid first impression confusion.
We'll see what the normal users (non-techies) will choose in a few months time once the invite system is gone and the web app is ready and how strong Twitter's network effect is against BlueSky.