A SV software engineer says there’s an easy way to determine who’s rich or not

>Do they have to work to live?

That is very vague.

So the guy who makes 400k isn't rich by his standard, but I, making a lot less, have some savings that would in theory last a while....so I'm rich?

If this is just about income in and spending out a very rich person who is a big spender could in theory be "poor."