I guess one potential axis would be 'stagnation', in the sense that social mobility between classes stops changing. That could be anything like straight up caste systems, or informal stratification from wealth getting locked up by the 1%. I hypothesize, that such an axis would be a measurement of how 'elderly' a society is becoming. When politics become too locked in due to unchanging political critters, the ability for a society to recognize and properly act in a situation becomes compromised.

My parent, they lost mental acuity and flexibility with the years, alongside their bodily agency, and have become quarrelsome. IMO, such dementia is what we are seeing in a aging America and the UK.