Finding evidence that disable people existed does not provide evidence that they were not able to contribute in some way. It's incredibly ableist to assume they couldn't.
In the context of a pre-industrial society? I doubt it. In a hunter gatherer-society? I doubt it even more. people with certain skills (e.g. tool making, music, cooking maybe..) certainly, but not for a lot of people.
However, decent human beings do not value other human beings purely on the basis of their economic contribution. Someone might be a net cost, but a decent society still looks after them.
You're missing things like making clothing (tanning, sinew, etc) , gathering wood, etc. You can be missing an arm or leg and still contribute to those.
I think we have a skewed perception of ability, now that we’re connected via the internet to the whole rest of humanity.
Nature is ableist in a lot of ways… if you had diabetes in some ancient tribe you’d basically be screwed. But if you had an amputated leg, I dunno. You could still be the best flint knapper in the tribe.
I mean, think of your extended circle of friends and acquaintances, your 100 “closest” friends. In particular, think back on the community grew up in, if you’ve subsequently moved to a tech hub that accumulates rare talent. I bet picking through your hobbies there are a couple potentially useful things that you’d be a top-tier contributor in. Most people are really bad at almost everything they don’t do, after all.
I’m not going to engage in some prehistoric idealism. The past was pretty brutal. But we’d probably all die by getting little infected cuts, not because we were abandoned by our tribes.
However, decent human beings do not value other human beings purely on the basis of their economic contribution. Someone might be a net cost, but a decent society still looks after them.