There’s a possibility the user whose story is in doubt is in fact very real. Most of us have flown with pilots who handle fatigue very differently from one another. So, extrapolate that and there are going to be outlier pilots who can do the freight-dog hub-turn life without consequences. I think the reasonable argument is that those people are fairly few and far between.
One of my best friends flies for FedEx and the amount of soft time and benefits he gets versus a legacy passenger carrier are pretty incredible. He commutes and bids seven day trips with deadheads on either side and a weekend layover; the result is that he is only actually flying about 8 to 10 days a month and can use his travel bank to create a PS commute to and from home. He flies the 767 and although he does not do too many hub-turns, he often flies at a different time of the day/night every day of his trip and feels pretty beat up for at least one or two days at home.
Comparing apples to apples, the narrow/mid body flying at a passenger legacy probably has about 15% of its total block hours at night, maybe less (San Francisco as an extreme example will have about half the pairings with an all night segment. On the 737 maybe 10% have two all night segments in a four-day trip and the union general pushes back against the company when they see those pairings. What this means is that for those who fly ANF trips, one of their four days is that night, but over half the pairings have no night flying at all). Saying that FedEx has plenty a day flying, may mean that 25% of trips have no night flying. But that means 75% have night flying, and to be honest and realistic, I would bet at least 40% are exclusively night flying, many of which are hub turns which are far more brutal than a single leg all-nighter.
FedEx is an absolutely amazing job for certain people, but your lifestyle is going to be fairly different than a legacy passenger pilot. Anybody who tells you differently, is either ill-acquainted or not being totally truthful