Notice the servants? The discrepancy between rich and poor? The bachelor living? The religious allusions? The repression? That’s all 100% Victorian England.
This setting allows Dr. Jekyll to become a more sympathetic character. It also explains why he needed to unleash his inner Hyde. Repression is no joke. In fact, you could go so far as to say that this book, because of its setting, provides social commentary on the place and times.