Very good that you care about the time people spend and that they get it back!
I just recently came across an article that working overtime is the no. 1 reason why employees leave the company (german article):

t3n.de/news/das-ist-der-grund-numm...

Short summary:

• Reason no 1: missing compensation for worked overtime
• Reason no 2: bad work climate. Collegial environment or the chemistry among the colleagues was not right (65% say so)
• Reason no 3: too much stress. Enormous pressure to perform, tight timings or goals that are too high (60% say so)