Ethereum is easy to change (hard forks often) and so cannot be expected to preserve any key characteristics like emission curve or even the permissionless nature.
In fact, Ethereum's monetary policy did change in the past.
In fact, Ethereum's monetary policy did change in the past.
who determines what's minimum and what's viable?
The social contract is that the protocol & monetary policy will ossify after the transition to PoS & sharding is complete.