Especially if you work long hours and still have a commute to get home. Add in a "honey do" or the homestead maintenance chores that you're not going to hire out to someone else (because Grandy and Pa never did!), and you start feeling like you have a broken back by the time you're 40 - 45...
I suspect the majority of rural semi-skilled jobs tend to be heavy in the physical labor, and yes, your body is going to give out and you won't be as productive as you were when you were in your thirties...and you don't get hired anymore, because there's always some kid out there or there's a new robot the owner can buy that can do your job more efficiently. Add to that, there's only so many manager and lead positions out there...so if you've made a good living just being a jack carpenter, a mechanic, or a small factory worker, you're SOL.
And service workers don't have it any easier. Try keeping a job if you're constantly in low level pain and don't have the skills to get into a schmoozing management job where you can get occasional rest for your aching body.
So yeah, if you have few jobs in the area along with marginal health or health care options to begin with, so you can't "live healthy" or "live active" like your grandparents who had enough subsistence farming that they could can or preserve excess to cover out of season availability, who didn't have to worry so much about competition once they got their job, disability appears to be one of the last options to keep a roof over your head and food in the pantry once you're over fifty.
I would never begrudge anyone access to disability, especially if their job options are limited to non-existent where they have settled. Not everyone can just up and move to where the jobs are, especially since jobs now-a-days require skills, flexibility, the ability to network and frankly don't pay like they used to.
On edit - Social Security Disability was designed for people who cannot physically or mentally be qualified to work jobs that are available. It certainly doesn't pay enough to live high on the hog on - at most, if someone is cheating the system, it gives them enough money to pay for medical insurance.
And it does not help that the definition of "ability to work" may not be adequate for what some lucky or authoritarian people feel it should mean.
Haele