The 4000 hours of 767 in my logbook would say otherwise. I never flew the 757 over the Atlantic, didn’t have to as we flew the 767’s there. But I flew it domestically and to Hawaii. And yes .80-.82 was the norm, just as .78-.79 is the norm for the 320’s (it can do .81-just that it is a game of chicken with the barber pole)
I agree the 757 and the 320 don't have the same performance. Just depends on what you want to measure. The 757 does some things better then a 321 (runway and climb performance, speed), and the 321XLR will do some things better then a 757 (like range and fuel burn/ maintenance costs).
The 321 should carry a similar number of passengers, with a much better First Class, therefore crew rest, experience. United has said the XLR will have aisle access for every lie flat seat. Again, if flying slower, then augmentation is more likely. And we get paid by the minute right?
SAS is flying the 321LR currently between CPH and IAD. Great circle distance of 3540NM. Blocked at 9:30 hours. The XLR will have more range so here comes 10-11 hour flights. And before you go “oh hell no, not that far in a narrowbody!!!”, what do you think was flying before widebodies existed? 707’s and DC8’s (UAL flew them BWI-HNL) and Dc7’s and Connies (holds the record for longest duration nonstop passenger flight-piston powered. A TWA Connie flight in 1957 from London to San Francisco was aloft for 23 hours 19 minutes! 5350 miles)
https://onemileatatime.com/news/sas-airbus-a321lr/
Anyways, the 757 is/was a great aircraft. Just that its time has come to join the history books like other aircraft before it.