Does the hadith: "It is sufficient sin for a man to neglect those he is responsible to support" apply to a sick retiree who is unable to work to increase his income, which is insufficient for his expenses?

The hadith referred to is that which Muslim reported from the narration of Khaithamah, in which it states: "It is sufficient sin for a man to withhold from one whose sustenance he possesses." And in a narration by Ahmad: "It is sufficient sin for a man to neglect those whom he sustains." This is explicit regarding the obligation of providing for those one sustains, but this is only conceivable for the person of means, not the one in hardship. So, if you are unable, there is no sin upon you, Allah willing. Blame and sin are only upon the negligent one who delays in striving despite being capable of it.