If a money supply remains constant while the economy grows, eventually the money supply becomes inadequate to facilitate trade throughout the entire economy. Consequences vary, but all are disruptive.
This is a fallacy! How money supply becomes inadequate? Money is a measure not fuel for economic growth. By increasing money supply as economy grows you are in fact rewarding a group of participating parties with extra money they do not deserve. You are creating bubbles! Bubbles are much more disruptive than slower growth.
but not increasing the money supply raises the value of the existing money as with bit coin.... remember with altcoin more money is being added but its up for grabs to anyone who mines?!?!
and decentralised currency needs miners.... plus adding just a little more forever more may encourage people to spend a little and not just hoard.... lets face it hoarding is only done as a means to get rich quick? or at least maybe fairly fast