Originally Posted by
ethernal
Do you have any data to support this? Pre-COVID, the US was filled with congested airports, jammed up airways (especially East Coast North-South routes), and unpredictable weather. You can certainly find global airlines that have better on-time rates but they are always based in uncongested regions and/or lovely weather (just like how Hawaiian Airlines almost always topped the charts in the US - despite being nowhere near as operationally mature as the majors). In addition, many other famous global airlines are single hub airlines. Constant out and back routes to mega hubs are operationally easier than complex meshed routing that bounces around hubs throughout the day. And if you are international-biased, many times there are long turn times that act as buffers to flight delays that don't work on short turn hauls.
Delta pre-COVID (and United was getting there) were also very good at not cancelling flights, especially when comparing like-for-like operational environments. You can argue about the definition (is a 20+ hour delay a cancel?) but few other airlines were as aggressive and creative at avoiding cancellations and/or started replicating tactics pioneered by US airlines (like enroute fresh crew pickups).
This isn't to say US airlines are great (or not great), but trying to compare them to less operationally complex airlines or those that operate in more favorable environments is silly. You can rag all you want on hard and soft product differences, but I don't think there is much of a leg to stand on when it comes to operational reliability.
The data is right there in the BTS website. In general, on time arrivals for US network carriers is in the upper 70% to right around 80% range. To me, that's a pretty poor number when it comes to reliability. No only that, but only at 15 minutes past schedule does a flight actually become
delayed by the US definition so there are plenty more flights that actually operate behind schedule that aren't taken into account, plus there's also the ridiculous amount of schedule padding some airlines (Delta particularly) use on top of that.
The US is filled with congested airports and jammed up airways, partly due to the way airlines schedule their flights, so that really doesn't take them off the hook all that much, and unpredictable weather exists worldwide.
Personally, the whole 'we don't cancel flights' song Delta used to sing was a bit of a red herring. As you mention, rather than canceling a flight they'd just delay it 12-24 hours which is essentially the same thing from the customer's perspective. In most cases there will be multiple other flights in that interim time. No, pre-COVID I could see an argue being made for Delta being more reliable than AA and UA, especially during AA's particularly terrible operational year. Now however, Delta stands out as having more operational meltdowns than most.