But the supply needs to grow & shrink as needed. If/when the economy shrinks, the supply needs to shrink.

Fiat central banks have very limited ability to shrink the supply that's why there was an oversupply of money when the economy shrank during Covid and we're still feeling the consequences of that.

Monero's only ability to shrink the supply is through attrition which is even worse.

Fiat central banks also have limited ability to grow the supply, mostly limited by interest rates not being able to be below zero.

Monero's ability to grow the supply is even worse. Especially during a purported adoption phase when the Monero economy grows massively the supply also needs to be massively increased for prices to remain stable.