Of course what's happened is that the capital and physical economies have decoupled more and more, so it's possible for ROI to circulate indefinitely between different schemes, becoming bigger and bigger and never actually being spent on anything tangible.

The mythology calls this growth and seems to consider it a good thing.

I think it's inflationary because at best its leeching value out of the physical economy, and at worst it's just a big Ponzi-shaped pile of IOUs.

You can of course still cash ou, but only if you do it before the pile collapses - which is useful for anyone who gets there ahead of the rush, but not so useful for the Bigger Fools who are a little slow.