I endorse a UBI. But why do you say "progressive taxation is bad"? Under a UBI + flat-tax system, a surgeon making 500k/year pays almost the same tax rate as someone making billions each year. A UBI + progressive-tax system will prevent this. I don't see why this is bad.
My own views on taxation are even more nuanced. I believe that the tax system should be designed to encourage desired (good for society) behaviors, and discourage undesired behaviors. Hence a better tax system would feature:
- No tax on income or investments
- Tax on consumption
- Progressive tax-brackets based on an individual's total consumption