Sure, the government has that goal too. But the government has many tools, and using taxes for that is using the wrong tool. Or maybe you think that billionaires owe us not only to pay taxes, but also to play nice, and pay those taxes with a smile on their face?
> pay those taxes with a smile on their face
The government's monopoly on punitive violence isn't only intended for the peasantry...
What are those other tools?
Funding the government, which has the goal to create a more just society, means taxes should support that.
If you're not using your funding to support your goals, thats corruption.
>and pay those taxes with a smile on their face?
Considering the alternative for them over the past millennia has been, inevitably that they get caught, hanged, quartered, beaten and other various violent methods: yes, they should smile, they're buying their lives with all that money :)
Billionares shouldn't exist. We shouldn't just tax them for the revenue. We should tax them to limit the undemocratic power that comes with excessive wealth.