You... probably don't? I continue to believe that there may be some small value in a single-person-instance-as-a-service product for celebs etc (particularly if Threads goes ahead with its embrace of ActivityPub; lots of value for celebrities in having the audience but having some independence from Facebook), but it's very niche.
Not everything has to be about making money, you realise.
It seems like a hassle to re-negotiate federation each time for each celebrity. What about a general PR themed instance (strictly moderated so that everyone will peer with it).
Thats actually a really cool idea. The big PR agencies who rep for actors, authors, musicians etc, could run an instance and that's where the person's identity would be.
Not everything has to be about making money, you realise.