The issue isn't The Wealthy having all the money. The issue is technology that will actively remove jobs. It doesn't matter if minimum wage is 90 pounds an hour if you don't have a job. An automated train isn't The Wealthy stealing money. It is a conductor out of work because their job could be handled by a raspberry pi.
Basic Income is a theoretical concept (been implemented in small, borderline meaningless, experiments) to combat that. Everyone gets a bare minimum "salary" regardless of if they work. That covers cost of living (how much more varies). Then, those with jobs have the potential to earn a lot more (incentive to work) on top of that.
What Thomas Piketty proposes wouldn't address the lack of income to those put out of work by technology but could, possibly, help to pay for solutions that would.
Take it a few steps forward. At some point the factory owner (whether local or conglomerate) holds all the money and has 0 workers. The only thing he can buy is new resources to produce more stuff, but no one can buy that stuff because no one works anymore.
At some point it's just a machine making stuff that no one can afford to use other than the very few owning the machine.
Money is useless unless it's spread around and in rotation through the system. The unemployment of uneducated is the one thing I really sympethize with in this election, but the solution isn't going backwards, because there's nothing there anymore.
I understand that the solution isn't one step forward, but maybe 5, and people will suffer in the interim, but that only means it's ever more important to swiftly move in the right direction.