Back in the old days aircraft didn't have the range and endurance they have today. A LHR - SYD flight would involve three stop overs with rest periods enroute and a longer time at destination, BA even had pilot postings.
These days 14 hour legs are quite normal rather than 8 hour ones. Time down route is minimised and 900 - 1000 hrs a year is expected rather than 600.
The figures given are for previous generations of Pilots who didn't work as hard. It would be frightening to see our figures in 30 years time.
Airlines could afford to offer a generous pension to those retiring at 65 as they wouldn't be paying out very much.