What difference would it make if it got dark at 5:30 pm in the winter? That's still too close to the end of the standard 9-5 day to make much, if any, difference in what you can do before dark.
In winter it's not about activities, just about the windows not being pitch black outside while you're still at work.
Sunlight coming in windows during the day improves our mood psychologically. I mean, it's the main reason we have windows at all in office buildings. (Windows are expensive and offices already have the indoor lights on anyways.)
And you pay for that hour in the morning when kids are going to school, adults are commuting to work, construction workers are working, etc. Indeed this is basically the whole reason we switch back and forth between standard time and DST.
