Complexity is priced, and it is priced badly when only one buyer is looking. A policy held in an irrevocable trust with three beneficiaries takes more legal work to transfer than a policy owned outright by one person. Some buyers price that work in. Others simply decline.
A seller with a complicated file who calls a single provider and hears no often concludes the policy is worthless. Usually it is not. It just needs to reach the buyers who handle that kind of file, and finding them is the job a broker exists to do.