FLSA is an interestingly-outdated animal. Basically anyone in a white-collar job gets an "executive" exemption. See: anyone working in financial services.

Meanwhile, in areas like retail, workers' lives are notoriously made difficult by unpredictable and arbitrary scheduling. So you're a part-time salesperson at Best Buy? Here's the 21 total hours you'll be working next week, spread out over 7 days because we need to cover little gaps here and there.

For better or worse, worker protection in the US is an illusion.