Sure we have it pretty easy but you are making a wrong comparison here. You can't compare the life and health standards of the early 1900 with our health and life standards (at least in the developed world). Things moved for the better not only for Software developers.
The right comparison is between you and someone who has achieved the same education/social level in the same period of time.
Not necessarily. His grandfather, while breathing and possibly ingesting toxins his entire life, did one thing most programmers do not do: exercise a lot. Yes, I saw the "work out at a fancy gym" part. There is a huge difference between going to the gym a few times a week and doing labor like his grandfather did.
My own grandfather did hard manual labor his entire life and drank whisky like a fish until he was in his late 60's. Chewed tobacco his entire life. When he was 88 I saw him working in the back yard and he had muscles that I didn't have at my prime (in my 20's). He died at 95.
I walk 4 or more miles a day, 7 days a week, some up steep hills. That's my commute, on the days that I go to work, my exercise when I don't. I really don't expect that I'm simulating my grandfather's level of exercise, but I hope it does something to get me to 95, in as perfect health as my grandfather was when he died.
You really want to measure life expectancy for people entering working age to avoid measuring infant mortality. Those numbers sound like they don't take that into account.
In logic, providing even one counter-example is considered refutation. Its tempting to do that with social/medical fields too. You're right its not statistically significant, but its absolutely, certainly data. An organism CAN survive extreme conditions, even thrive.
For example, claims of necessary action based on real statistical data are unwarranted. The existence of populations that thrive in the so-called 'unhealthy environment' do show there are more variables at work. Who's trumpeting "we should all work like 1800's laborers for good health!"? Nobody, but not because its not true. Because we're lazy-ass modern narcissists who want a quick fix.
The right comparison is between you and someone who has achieved the same education/social level in the same period of time.