The article doesn't paint quite the rosy picture:

"The best time to fly is between 6 and 7 in the morning. Flights scheduled to depart in that window arrived just 8.6 minutes late on average. Flights leaving before 6, or between 7 and 8, are nearly as good.

But delay times build from there. Through the rest of the morning and the afternoon, for every hour later you depart you can expect an extra minute of delays. Delay times peak at 20.7 minutes — more than twice as long as for early-morning flights — in the block between 6 and 7 p.m. They remain at 20-plus minutes through the 9 p.m. hour."

It's been several years since I looked at the data, but if I remember correctly most flights actually arrive ahead of time. The median if I remember correctly is actually negative (ie. at least 50% of flights arrive ahead of time).

However, this means that there's a long tail of flights that get delayed an hour or more, which brings the average up. Not a good situation to be in if one has to make a late connection during the day.

It's a little disappointing that 538 didn't talk about the distribution on this.

I'm looking to avoid the one flight that's delayed an hour that means I miss my connection because my layover was an hour. Only 5 flights have to arrive on time to hit an average arrival delay of 10 minutes. Those are not favorable odds, as I see them. Especially if it's cutting into my vacation time.

Yes, missing a friend's wedding or an on site interview or ..., because no more connecting flights until same time tomorrow, with a probability 1 in 6 is pretty bad odds