I disagree, currency can be created and destroyed.

Money (the measure of wealth) is absolute. You may wish to use a different word, I would not argue this moot point.

I think this is the fundamental flaw, we believe money can be created and destroyed simply because we are used to printing or burning government fiat and have copied that model for Crypto currencies like Ethereum or Thether, which are mined or burned.

So no. Money (invent better word) cannot be printed or destroyed, it is a measure of wealth and if you increase or decrease the supply you change the unit measurement, not the money.