It's hard to assess the overall quality of a major airline career because the industry is so cyclical. Two pilots born only a few years apart can make exactly the same decisions as they move up the ladder but still wind up with wildly different careers. Timing is huge, and while you can do things to stack the odds in your favor, you need to be willing to risk not having the career you wanted, even after doing everything 'right'.
Yup... This is spot on.
This career is a dice roll. My old man was a Pan Am guy that went over to Delta when they bought the Atlantic routes in early '91. If you told him, when he got hired at Pan Am in '66, that he'd retire from Delta 30 years later, he'd have laughed at you, as Delta was not much more than a regional at the time.
I've done pretty well in this business, but a
lot of it was luck. I also heeded some great advice from my dad and others coming up, some of which made a huge impact on the course of my career. I can name dozens of my peers that went different ways, and ended up starting over in their 40's when their airline went belly up.
I was lucky, and got my furloughs and Chapter 7s out of my system before I was 30. I worked in MX, line service 135 charter, corporate, 135 airline, 121 cargo and 121 airlines. The best job I've had, by far, is the 121 airline stuff. I've been at my current airline for almost 19 years.
The best advice I can give is to get as much time (preferably MEL PIC turbine), as soon as you can and always take the earliest class date. Seniority is life in the airline world. The QOL and pay at the first jobs is going to suck, bad, but it is a means to the end. Just suck it up, work your butt off and the hours will pile up, allowing you to jump to the next tier.
Also, never commute.....
Move to a domicile when you are relatively certain the job will be around a while. It'll be a 100% improvement in QOL and in many cases, a nice pay raise.