They just round more than you: I think your presumption that others should think like you is bizarre. Some people only round to 10 cents. If you are wealthy enough, you could easily round 10.99 to $0.
What I actually wrote was "bizarre to me", not just "bizarre" (as in your quote), so I don't think it's fair to say that my comment conveyed such presumption
But I live in a very dense city (Chicago), it’s become almost “set your watch to it” reliable that not only are estimates more reliable from friends who live here when they say “I’ll be there in 8 minutes”, they’re also seemingly more likely to offer such a precise estimate because they know the area, light timings, and traffic patterns and that certain kind of behavior found among drivers in this city.
Compared to when I have friends from out of town renting a car they’ll tell me “GPS says we’ll be there in 10 minutes” I instinctively add another 10 and it’s never failed that they’ll show up and go “that was a long 10 minutes!” And I just smile.
It was practically a given that the first time someone visited they would arrive 15-20 minutes later than they estimated. It seemed like an area without a lot of traffic but it was in that uncanny valley where there’s enough traffic where you catch a lot of lights, and you aren’t turning right on red because there are people in front of you, and you may or may not make the left turn light on the first cycle.
Also the whole city is so tuned for one direction of traffic that it takes longer to go across the narrow dimension than the long one.
There was a movie theater that I found I could reliably get to faster on a Friday evening if I drove five blocks past it and doubled back, the lights were that screwed up. 15 blocks faster than 5.