There are people for whom the difference between $10 and $10k is effectively immaterial. These are the people I bin as “rich”, and I think that’s how we should all see it.
While someone making $500k/yr is definitely prosperous, the “rich” are an entirely different category of individual. It only serves the more selfish interests of the truly rich to conflate the two.
I think the tricky thing about it is that income / wealth distributions are exponential, so no matter where you are on the curve, it basically looks the same. The people that have more than you have massively more, and the people who have less don't really seem to have that much less.