I commute 8-10 miles a day to and from work in Chicago.
I like to sit upright while riding.
I'm comfortable being the slowest person in the bike lane 10-14 mph average.
People say I carry a lot of weight when I ride. (i.e. lunch bag, change of clothes, work laptop).
Don't know how relevant this is but I work in the Loop so traffic is for real every single morning.
Lights are a big deal. In Chicago, if you ride 3-4 seasons, a lot of your riding time is likely to be in the dark. I use good dynamo lights (B&M) augmented by rechargeable battery-powered headlight, taillight, and helmet lights.
I also like internal gear hubs. Derailleurs are not so very hard to keep clean and lubed, but with an IGH you could use a Gates belt instead of a chain. Disc brakes might be a good idea, too, but I've used mostly cantilevers and have never had a problem stopping.
For a new, off the rack commuter bike, I'd be tempted by the Breezer Beltway 11+, or something like it. https://www.breezerbikes.com/bikes/transportation/beltway/beltway-1...