I’ve looked back over your links and do not find any unqualified claim that people in the 70 - 50 range can live independently. I found a few claims that with sufficient training and education they might get by for some period of time–training and education that would hardly be available to 50% of an entire nation.
Your later remarks in response to Telemark simply reinforce that idea. It seems that you would like to dismiss the efforts of the Lebanon Group Home on the grounds that it is, somehow, more dangerous to live in a society with clean running water, USDA inspected food, 24 hour electricity and gas, and similar accommodations to all people as opposed to living in places where those things are either non-existent, intermittent, or significantly impaired and which have a greater number of venomous or otherwise dangerous animals and far less competent law enforcement.
So we start out with people who are given as many years of education as a lawyer or an engineer (obviously following different curricula), then work with them to engage in some undefined level of “independent” living, (recognizing, of course, that
So, the families (those members with IQs closer to the 100 norm) are expected to participate in the support for these individuals while some substantial portion of their livelihood is provided by the state.
We also see that this particular facility is providing training for only six individuals at a time, while the same governmental agency is proving a host of other services for the entire range of other people at even lower IQs. They do not expressly say it on that web page, but in my county, “independent living” merely means the ability to live in a house or apartment without direct, daily supervision for cooking meals and washing clothes. However, everyone in my county living “independently” still has a caseworker who ensures that their grocery shopping is adequate to maintian a sustainable diet, that the correct portions of SSI and wages are set aside to pay bills, (some of which are directly taken by the service or product provider without the individual actually ever seeing the funds), and that deleterious changes to routine are corrected before they become health- or life-threatening.
I am not sure what Telemark’s position might be, but I see no inconsistency in noting that IQ is only the roughest gauge of intelligence even in Western society, that people who display the level of intelligence roughly assoicated with a score of 70 could not function as a society regardless whether they were in the West or elsewhere, as well as noting that the tests administered in other cultures are liable to be even less accurate than those administered in the West.