So whatever you believe is at fault for the failures of human rights treaties, we can ask ourselves 2 questions:
1. Do they really matter? (Of course!)
2. What policy recommendations can be made to help countries achieve the goals set out in these treaties?
The first question seems to be dependent on the second one as if it is possible to fix the problems of human rights treaties; they are able to matter more.
If you feel that the problems with human rights treaties is that smaller countries do not get enough assistance and support from wealthier countries in order to achieve the goals set out in the treaties, a multitude of ideas could be recommended. Among these, there could be an international convention that is enacted when signing these treaties that the wealthiest 5% of countries taking part in the treaties have to put up a pot of money in order to assist the bottom 5% of countries involved in achieving the goals of the treaties. This can be amended for smaller or bilateral treaties that the richest country helps out the poorer countries.
If you feel that the problems of human rights treaties result from the lack of enforcement then another set of recommendations can be made. For example, there could be more enforcement agencies, regulated by an international organisation such as the UN, to specifically make sure that countries taking part in human rights treaties are complying with the terms of the treaties, especially at a local level where many infringements take place.
So do Human rights treaties really matter? To me they do. Despite their success, their notion to help people in countries where human rights are abused is greatly admirable, and their problems can easily be resolved in order to create a system where all parties involved have a reasonable chance of achieving the goals outlined in the treaty.