Doing things sustainably, so that they continue in an ongoing way, without using up necessary supplies and without rendering the larger environment toxic, makes a lot of sense. Helping individuals or groups learn to take care of themselves in this way makes a lot of sense, too, and the work can be very rewarding.
But working to effect these positive changes in others is demanding. It requires thoughtfulness, which in turn requires time. It also requires many other things, which depend on the particular ecology of the system, but which may include money, strength, patience, and good will.
So a real challenge, which seems to be overlooked or even intentionally ignored, is this: how to sustainably work for sustainability. This is as real a challenge for organizations as it is for individuals.