I support life sentences. Not death sentences.
Killing billionaires is not a matter of deciding whether those billionaires deserve death: it's a matter of choosing your allies.
If you are able to take a billionaire's property without taking their life, and you choose to avoid killing them, then your allies will be people who spare life whenever possible.
You need those people as allies.
If from the start, you advocate for separating billionaires from their property without killing them, then you will attract the same allies described above.
Once again, those are desirable allies.
If, on the other hand, you choose death when death is optional, then you will align with allies who approve of unnecessary killing.
Those allies are not desirable allies. Those should be your enemies. Those people should be deprived of all weapons and power and if necessary, locked away.