You mean to tell me that the history of all hitherto existing society is the history of class struggles?

Both Medieval Europe and Antiquity were defined by wealthy landowners and poor workers. We don't always see a whole lot of that in the writings that have survived until our time, but that doesn't mean they didn't exist.

Most of the ancient sources we have were written by people with the both leisure to learn, travel around and write stuff down and the connections to have their writings be considered worth duplicating and preserving. In a word: the elites.

The issue here is that the poor and destitute didn't exist in a vacuum just because resources were scarce. Even in bad years for the peasantry, the elites generally did fine.

These ancient sources don't always spell that out, because it isn't worth spelling out to them: this is just how they and their peers live. Most of these elite members owned property or the workshop and tools with which their workers labored.

By and large, they were rich. Whether that richness is defined in numbers on some net worth estimate or just in the amount of things they owned, the result is the same.

And even in Ancient Greece, the rich had to make some contributions back to the community (except for Sparta, but they're a whole different beast of exploitation). Philanthropy has its roots there, even if it is a far cry from what we would term Philantropy today: The wealthy either voluntarily or out of obligation funded buildings, artworks etc. for the general public.

What changed with Industrial Capitalism and later Globalisation was mostly the scale of exploitation. But the principle - an owner class exploiting a labour class - has been around forever.

Capitalism is an evolution on previous class societies, not the first one, yes. Socialist countries have eradicated poverty with comparison to their pre-Socialist systems, and that can and should be recognized.