That is not the point, and the comment you’re replying to gave some very real, serious examples as to why not. Cost of living alone eats an incredible amount of your budget unless you’re very well to do, so there, immediately, you’re out of “sometimes” territory. We’re already in “the majority of most people’s budget” land. Then you have payday loans, any kind of loan in general, late fees, etc: all of these are costs to low liquidity. Unexpected expenses cannot be absorbed if you have no cash nor assets to sell. Being poor is expensive; this is not a random anecdote, it’s a fundamental character flaw in our society that has been consistently identified and documented. Google “the cost of being poor” for more reading material than one could process in a lifetime.
If you’re talking about the specific example in the quote, alone: it’s an illustration, to make a complex and ugly point understandable and palatable and easy to digest. It’s not a random data point: it illustrates the mechanism by which being poor is expensive. That’s not straight forward to intuit, hence this example has merit.
this has not been true for a long time by now. If it were true there would be no mass market for tourism and no budget for so many people to buy iphones every year or two. By far we all earn way more than what we strictly need to live, even in your first jobs in your twenties.
That assumes rich people actually participate. They could also just buy cheap things over and over because they can. I like to do that so I'm not too emotionally and financially attached to possessions, which becomes a liability and a worry.
To be clear, I don't think it's strictly wrong, just that it adds nothing of value to a conversation. It just gives a very specific example of when a rule holds.
It's kind of like if the employment statistics come out, and they show improvement, but someone comments that they just got laid off that week. They aren't wrong, but they're also not adding anything to the conversation.