Billions of $$ in global fiat currencies has been exchanged for crypto. As long as someone sells some - which means someone buys it from them … crypto will continue.
China is the biggest mining operation for bitcoin out of Texas. It will rise and fall and rise but it will never be zero.
The USD is merely work credit.
The big covid “coin shortage” was due to all the coins with real metal value were plucked from circulation. Once they had purged the value from the coin supply suddenly there was no shortage.
Your coins and dollars are merely worth your agreed upon work credit value but not the metal value which will gain value in the future.