The government is going to take all that new tax money from the billionaires and do what with it? Do you believe the government can efficiently manage the tax revenue to help the poor?. SF gov spends $60k/year per tent for the homeless [1] ..that's called a mismanagement of tax revenue (and probably massive corruption).
Because they take a lot of value out of a shared society and concentrate too much power on their hands.
> What are you going to get out of it?
Reduce the power discrepancies, mostly, and money too.
> Do you think taxing the billionaires is actually going to help the poor people?
Yep.
You are asking about government efficiency, but one of the reasons for the lack of efficiency is that billionaires do not want it.