> Central banks were created because without them, finance was subject to wild, terrifying, ruinous boom/bust cycles.

Let's see how that is working out:

  Federal Reserve created in 1913
  Roaring 1920's -> 1929 Crash/Great Depression
  1960's Nifty Fifty -> 1973-1974 Crash/recession
  1980's bubble -> 1987 Crash and early 1990's recession
  Dot Com bubble -> 2000-2003 Crash/recession
  Housing Bubble -> 2008 Crash/GFC
  Everything Bubble -> ???

At least since the 1987 crash, artificially low interest rates from Central Banks and more recently outright money printing/QE enhanced or outright created the bubbles and busts. Even when viewed in the most favorable light their supposed moderating function seems to be horribly broken.