At the place that I interned in software development, there was a period of time before I was there where the hours were starting to creep to long enough that the workers (salaried) were effectively being paid less than minimum wage. Legend has it that there was a mention of a lawsuit if the company didn’t shape up. One coworker who had been there at that point described it as a dark point in the company’s history. In response, they temporarily switched to hourly and 40 hours a week.
Later, some people apparently started working over 40 hours a week of their own volition. Workaholics, I guess. At the behest of one of the people on my team, the CIO talked to them about sticking to normal hours. Part of it was that people just aren’t great developers after already working a long day. The other part was that no one else wanted to slide back into those long working hours. A few people also had had kids in the intervening years, so I don’t think they wanted to see their hours eaten by work.