If you are leaving school you might be lucky to retire on a widebody let alone know what fleets will even exist in 40 years.
10 Years in GA/Regional
5 Years Regional Command
10 Years Narrow FO
10 Years Narrow Command
Then Widebody Command
Age- Prob 55-60.
On the Health front, I couldn’t imagine slogging out 30 years on the current EBA.