Look at the European crews when you see them in customs. They all seem relatively young. The senior (old) guys are flying narrow bodies around Europe with shorter legs, close to home with few time zones and making the biggest bucks. Works great.
I for one would be happy to never fly another international trip. I much prefer domestic but fly international because it's the best money. To me taking off and landing is a lot of fun, the rest is pretty damn boring! On the other hand there are thousands that would LOVE to fly widebodies on international routes that will never get the chance due to seniority. If the pay were what you can hold instead of what you are flying I would be much happier on the S80 or 737 freeing a wide body spot for one who would enjoy it more. It would be a win / win!
CG