This really resonates. In my experience, the legibility trap often shows up as a trust problem. This is why I am interested in the connection between evidence, impact, and relationships. 

The reason I focus on trust is because the research shows it is the x factor for effective implementation, sustainability, and impact. The connection between efficacy and trust is highly studied across multiple sectors. The for-profit sector is very focused with tracking internal and consumer trust because it can be one of the most impactful factors for running a successful business. Trust is not sentiment - it's the relational infrastructure that determines whether an intervention can actually be implemented and sustained. It can be as measurable and valuable as many other success metrics. Notwithstanding, many of us have experienced the time and money wasted when trust breaks down. There are some outdated studies on this but more inquiry is needed to really demonstrate the cost of broken trust. 

I'd love to see lots of different philanthropic models test what is possible. It would undoubtedly spark some important evolutions in strategy, measurement, and impact. The question is whether we are willing to test a rigorous approach to building diverse and proximate relational networks that can accelerate effectiveness (and include bridgers of course, as you define them). The research shows this approach is a resounding yes. I am curious to see how practice follows!