Do less than 100 people on Earth have taxable monthly income (which can be used for UBI) same as half of world's population? Or same income as UBI for half of world's population? Net worth is irrelevant.

It's far from irrelevant. It's the core of the problem.

I don't give a cp about taxable income. They should not have that much power. Period. Take it away from them and put it to good use.