Time is a fixed quantity for poorer people. If you don't show up to your 8AM Walmart job on time, you'll get chewed out.
But if you're a senior VP, you can move meetings around to fit your schedule.
First, the article doesn't appear to talking about actual rich people (billionaires, etc) but upper-middle-class white-collar people (i.e., they still have a day job and can't live off savings & interest). But, we can call them rich to keep it easy.
In a literal sense, rich people have more time, as they tend to live longer than poor people.
In the sense of day-to-day free time, I'd argue rich people have more. Both in absolute terms - they rarely have to work two jobs, though they might do occasional OT. And in their ability to time-shift work obligations. Take a software dev - typically they have flexible work hours, might have some ability to schedule their own meetings, and nobody blinks if they duck out early once a week for a long run/ride/whatever.
https://www.theatlantic.com/business/archive/2016/09/the-fre...