> If billionaires and aristocrats were actually a sizable amount of a country's wealth

I might be misunderstanding your point, but I think they might be? E.g. in the UK:

> By 2023, the richest 50 families in the UK held more wealth than half of the UK population, comprising 34.1 million people

https://equalitytrust.org.uk/scale-economic-inequality-uk/