Shirley: what difference does it make to us- *the ones who already know it is a futile endeavor*if the methods are ineffective. We are not doing it. We know lives are not at stake.
The effectiveness of the methods, or lack thereof, is not the issue. The point is, JWs are trapped in a system of man-made rules that enslave them to a schedule and lifestyle they may not necessarily agree with but abide by under compulsion/duress in order to comply with the demands of their leaders. While lives are not at stake, as you correctly pointed out, lives are being wasted. And, many here still have family and close friends in the WT Org, and it is painful to watch them waste their lives in futile endeavors.
It makes me livid to watch my still-in family members donate money they cannot afford to donate, and spend what little time and energy they have serving WT's interests, not their own. They put health, dreams and happiness aside because they have been convinced by WT that that is what God requires them to do. That's why I care.
It is bad enough that WT demands people's vital energy and lives...but made so much worse that the same energy and life is being spent on increasingly absurd levels of ineffective triviality and "busy work".
what choice do they have
You said it. When a person no longer has a choice, then they are a slave. I, for one, am not a fan of slavery. That's my answer to your query, "what difference does it make to us?"