What Is ‘Ultrasound Money’ in the Context of Ethereum?

'Ultrasound money' is a term used to describe Ethereum post-EIP-1559 and the Merge, where the burning of the base fee often leads to a net deflationary supply of Ether. This deflationary characteristic is seen as a superior monetary policy compared to 'sound money' (like Bitcoin's fixed supply), implying a potentially higher long-term value.