It looks to me like a principle - the more unequal a society is the more unstable it is and the more people and the biosphere suffers.
A way to address this would be to pin the uppermost earnings with the lowest. There must be many mechanisms whereby jobs are ranked. Financial institutions, actuarial data, HMRC etc. Perhaps it would be something for a Citizen’s Assembly to work out.
We could have a society where the top earners are on (let’s say) 50 times the bottom earners. Perhaps exceptions could be made if someone came up with a really, really good reason and had a majority agree, but in general, what justification could there be?
What I’m envisioning is a society that husbands its resources rather than plays the winner-takes-all game. The humans need to start asking what they give more than what they get in relation to the totality.