Let’s be very clear about what the problem is-
Wealth is power and after basic needs are met it is lack of power that is poverty.
Income, intergenerational transfers, and appreciation of capital assets once obtained, are the primary means of accumulating wealth and thus power.
Currently wealth and thus power is being dramatically concentrated within the 0.01%, and to a lesser degree the 0.1%. The rest of the 1% is at least not losing wealth but pretty much the rest of the spectrum is.
With that concentration of power in the hands of the very few more and more are relatively powerless in comparison, thus iPads and Galaxy Notes notwithstanding, are serfs. A few knights perhaps, but knights who are at the command of the very few Lords and Ladies. A slave who lived in the big house, got to wear nice clothes and eat well, was still a slave at the end of day.
The 0.01%? Predominantly from the world of finance.
Addressing the income gap is an important part of addressing the real problem but it is not the real problem itself. The real problem is the power gap that results from the dramatically increasing wealth gap of the 0.01% and maybe the 0.1% and the rest of us who serve as their serfs (some well fed, some not) in an increasingly feudalistic society.
And the Lords and Ladies? Not evil. Just a fair reflection of human nature. Some quite brilliant and some quite decent people. Some realize themselves that massive intergenerational transfer of that sort of power is bad for society and are instead using their power to accomplish societal goods instead. Doing that is frankly above and beyond what a cynic’s view of human nature expects. That some use their power to work towards concentrating more, for themselves and for their children, and towards competing with others in that class for more power … more expected … so long as the system fairly allows for it. Which they, with their massively increasing power, will work to increasingly allow it to do.
Larger estate taxes on those most extremely large estates is not primarily something that will raise lots of revenue, but it does decrease the intergenerational power transfer. It encourages giving it away to good works instead. And their next generation still has the capacities passed on to them by the values, habits of mind, education, work ethics, innate creativities and intelligences, and a still quite large seed fund, to make their own megafortune.
Investing so that all can have the education that can optimize their contributions to society (and thus achieve an ability to have some power within it) is good for society by addressing the power gap.
A return to a more progressive taxation system (over time it has become significantly less progressive) also works towards reducing that gap.
A modest transaction fee is not in fact going to raise huge funds, but it is a Pigovian tax, as rapid milling of stocks, currently often done by computerized programs with extremely short hold times, is of harm to economic stability.
But again, income inequality is not the major issue; power inequality and the resultant feudalization our society is. Increasingly one out of 10,000 are the Lords and Ladies. That differential is unsustainable.