I think the ultra wealthy will have to leave their apartment at some point, and then they’re vulnerable.

Also, what’s even more important is that the rich own all their wealth in the form of company shares and real estate, and that cannot be moved inside a bunker because it fundamentally has to face the outer world. In other words, the billionaires can hide in their bunkers their entire life for all i care, but the publicly accessible infrastructure that they own is gonna get taxed in that case, and that is just as well.