Jeffrey mistook Piketty's 5% as meaning GDP growth, but that is g in r > g. R is capital growth, which he contends is typically 5% in the historical record available to him.
Two factors need inclusion, the overall population growth, and the effect of inequality on social structure. The first suggests that if an economy grows at the population rate, value is stable. If population accelerates, more bidders exist for land and resources, so housing goes up, wages go down. The second factor suggests that, if status affects things like mate choice, control of resources, and emotional stability, it really does matter to keep up with the Joneses. In that case, seeing an impossible Empyrean is depressing and/or enraging. This predicts social decay as well as rampages that do a Hail Mary for reproduction (rape) or status (violence against the top).
In order to care about the future and to work toward ensuring success for one's offspring, there needs to be some confidence in opportunity. If the future looks to be shrinking, foreclosing options, apocalypse may be preferable. I see this process in the Middle East.
Economists, like astrologers, might prefer to tell the wealth what it hopes is true. This would mean more employment opportunities for them. Piketty has a more secure employment than American economists, and can safely say we should tax static wealth. I agree; we already do this on property. I think UK taxes on property increased to support the war costs of WW I and WW II, and to pay for the enlarged welfare state. This would be a significant factor in devaluing property as wealth ("land-poor"). The breaking up of large estates spread the wealth around.
I learned an important lesson from "Capital"---the US has about 5 times as much wealth as government debt, and our national income is roughly equal to it. This is like having a yearly income of $100,000 to set against your $100,000 mortgage balance, with $500,000 in equity on that house. A sweet situation, I'd say. "We" are rich", but you and I are not. Sneer at someone who says the money is not there.
The reason interest rates are low is that there is so much wealth looking for that 5% return it floods the CD/bond market. Thus it chased new bubbles of dot-coms (90s), oil futures (early 2000s), and securitized mortgages (later 2000s). "Quantitative easing" did not cause inflation because it was not just giving everyone money (which would), but letting bondholders cash in early. That money was not given out but again simply rented out.
Large wealth holdings are like a black hole---the money never comes out again (you never spend your principal). But one can extract some useful energy ("useful" being the important factor) from a black hole, by swinging close to it and tossing some mass overboard. You get a momentum boost at the expense of mass. That is the interest on the loan---you get the useful money at the cost of the real money. In principal this can create more wealth, as in a savings and loan bank financing new construction from its deposits. Eventually the money is paid back and there now exists both the original money, the repaid loan, and the house.
There is probably a sustainable interest rate that reflects the population increase in that little town, and would not impoverish the borrower or not reward the depositors. But now the small depositor gets bupkis, while the banks' major shareholders get 5% from those securitized mortgages.
The people that say the poor have toilets, or TVs, or cellphones, so they aren't really poor, are either idiots or liars. The social dynamics of hierarchy scale with the living standard---even though a homeless person has more clothes than an Amazon rain forest Yanomamo, he is still poor while the Yanomamo might be a tribal chief. I doubt the chief would trade places, while that homeless person just might. Warm climate, status, mate choice, children---hmm.