I'm a runner, but the biggest things was the parks and our infrastructure. I realized why we rank so high in parks and how glad I am to be near the Grand Rounds and to be able to run around our lakes and the river. I also thought our infrastructure on averaged seemed to be better maintained, but we have some advantages there of being a younger city.
I too am a runner, and I've made a point of trying to run in other downtown areas while traveling for work. Nowhere I've been comes close to what we have here.
A lot of cities have little areas with nice paths etc. Like I was in St. Louis this summer and the new Arch Grounds are very nice, but if you want to do a 4-mile run in downtown St. Louis that doesn't involve city blocks or creepy isolated and unpleasant train corridors, your only real option is to run back and forth across the Arch Grounds.
Kansas City has a nice and newer path by a river, but it's not close to anything, is relatively isolated and not terribly long.
Pittsburgh was overall a neat city but the only real running trail I found was a pretty industrial route across the Monongahela that I recall just kind of ending in a random spot.
San Jose had a linear park that was kind of cool in a "California vibes" kind of way, but also kind of isolated (ie creepy) and not very long.
Anaheim had a trail I considered driving to, but then I found a few online reviews with key words such as "Mad Max" and "man with a whip," so ended up sticking with the hotel treadmill. (Aside, but Anaheim might be the worst major American city I've visited.)
Phoenix (another city I didn't like) had a man-made river with gravel on each side, which was fine for like a day. The trail also had no barrier before a 45-degree hill down to the water, which was a little concerning. Another day I found a random park and ran back and forth like six times. (I suppose neither of these are really "downtown" running, though)
Even Boston I found to be surprisingly mediocre. Staying at the Marriott in the Back Bay area (ie a great location), I ran up Commonwealth Avenue and into Boston Common (because that sounded like it'd be a cool thing to say I did), but that was like a mile. I eventually found my way to the Charles River, where there was a trail that kind of had armpit vibes, tucked behind a larger road and without great access. Looking on Google maps it appears the trail continues on and gets nicer, but I was surprised it wasn't better right in the heart of town like this.
Probably the best running I've found in a different downtown area was in Indianapolis, which had nice enough trails that seemed to go on for a while, but the White River isn't much to look at and is pretty undeveloped. It definitely feels more like you're running in a mid-size college town than in a major city.
I've often wondered to myself when doing a loop from the Franklin Avenue bridge -> East Bank -> Stone Arch Bridge -> Gold Medal Park -> Bohemian Flats -> Franklin Bridge whether there's a better urban running city than Minneapolis. The run I just described really has it all, and while you do have to run briefly in a no trespassing zone I think it otherwise has no road crossings. Or instead of crossing at Stone Arch, going through St. Anthony Main up to Nicollet Island and then Boom Island, then run back through the North Loop. I think that adds maybe one additional street crossing?
If you expand outside of the downtown area, obviously, you find so many more good urban running trails.
Chicago people always like to share pictures of their lakefront paths, which to be sure do look nice. I don't have personal experience running on those trails, but my sense has always been that it might become repetitive to run there everyday. Maybe there are good side paths, though?
So yeah. I guess I've been sitting on this take for a while now, just waiting for somewhere to drop it, and here we are. If this is distracting maybe "city running" can be broken off into a separate thread.