This is not exactly what happens. Everything that a central bank does is done in the name of the stability of the economy it is supporting.
essentially that's not incorrect per se, that's why most of the central banking and financy ministry staff might do their work in good conscience. They try to regulate and balance the over-all money supply with their setting of the prime interest rates in the purported best interest for society following the ideas of Keynes (even he would turn in his grave though if he could see how they pervert, i.e. overdo his ideas).
however, what OP criticizes is rather how it all started: monopolized fractional reserve banking, which has always been an opaque practice to put it diplomatically, if not an outright scam.
it is what caused bank runs, and central banks were invented to fix this problem; central banking as an institution is therefore just another case of trying to fix symptoms rather than causes.Fractional reserve banking allows to create money "on the fly" as needed by the economy. If we removed FRB, then this would likely prevent bank-runs, but without it the economic growth would be hindered. Is there any other
automatic means to provide the growing economy with the money it needs that would be as effective?
Fractional reserve banking is what allows the economy to grow and what allows most people to borrow for things like houses and cars, and to borrow in times of financial emergencies.
I wouldn't say it helps the economy to grow, although in a way it does. It allows for bigger and better numbers, but it also takes away from purchasing power.
And it is sadly what people now have to use when it comes to borrowing those things, it would have been nice if there was a set amount, like what the gold standard had. They did fine before 1971. I don't see what would have changed.
We could very well have a good society where we didn't have to have Fractional Reserve Lending or any of this, especially if it was a full-on libertarian or Peer-to-Peer system.
Jack cuts down a log, sells it to Bill who runs a construction company, for $1. Bill uses the log, and generates $2 from his client. Now, if Jack was in trouble, he could chop down many logs, and earn $5. Bill would use these up eventually, as he would earn $10 in other services or goods from his clients.
(Key thing is that when I show stuff in dollars, I mean in value, not necessarily actual money)