People assume that capitalism is a system defined by markets and trade. But these pre-existed capitalism by thousands of years. What distinguishes capitalism is that it is organized around perpetual expansion and accumulation, which is euphemistically referred to as "growth".

This requires:
-enclosure to generate proletarianization
-artificial scarcity to generate competitive productivity
-an extractive relationship with nature and labour to enable surplus accumulation
-"frontiers" where nature and labour can be cheapened and costs externalized

Such a system is incompatible with ecology, and incompatible with any vision for a world that's free of poverty, exploitation and structural inequality. We need to have an open conversation about whether such a system is actually worth clinging to in the 21st century.