This was my exact case but from the side of the employer.
I run a small UX company. We have 7 employees who used to work 8 hours a day, 5 days a week. At some point, I noticed that everyone, including myself, was not very productive. Also, I noticed that the stress load was really big.
Since my partner is a PhD in Psychology, I asked her to see if she could improve the process. The answer was very simple:
Being that our work demands a high load of creativity and thinking solutions, analyzing data and turning them into creative form, with constant changes between digital and physical environments and the cognitive load that this represents, our level of stress was very high and it was impossible to perform as we should for 8 hours. Worse yet: given that the stress is cumulative, we could not start the next day "clean of stress", but accumulated the previous day's stress.
The solution? She asked us to take a week off, and when she got back to work she measured our response levels at work for 3 weeks, filming the process. She discovered that we were actually working only 4 hours a day.
With this discovery, we reduced working hours to 5 hours a day (I continue 8 or 9, but because I like it, not by obligation). Our productivity and our quality of work took a very remarkable leap, almost immediately.
A year after that, we added the possibility of an additional day off every 15 days. In no case did the employees earn less, we simply optimized their time. Additionally, since creative people tend to fall asleep very late at night, 5 hours start at 1:00 PM (although one of them starts at 10 AM). So they don't have to stop for lunch: they're supposed to have lunch before start.
Of course, in case of a deadline or some trouble, they have to work normally, but they do not take it as a burden anymore: they know that it is an exception, and that this exception is what makes these schedules they allow them to manage their times and work fewer hours.
I am not saying that it is necessarily the case of the OP, but I found it interesting to give a perspective "from the other side", since that may be what is happening in your case.