That is actually, quite literally, inflation. It's money depreciating in value relative to stocks and financial products. Just like a burger at the golden arches shooting up in price is inflation, so is the price of a stock. It's probably not _only_ inflation, supply and demand will have caused the majority of this shift, since savers saw their money start evaporating. But that is of itself of course a second order effect of inflation, so I think the point stands.
Sure, but the only kind of inflation that really crushes people living off their investments is stagflation, where increasing prices of goods is not reflected in portfolio sizes. If your investments are growing way faster than the price of goods, there is no problem.