Being fraught with potential for abuse by repressive governments and repressive corporations is an interesting take on the current system. This is one of those areas where no matter what system is in place a difficult to define fine line will exist. The converse - a set of government anointed entities - is very likely to be vastly worse. ICANN anyone? As soon as governance becomes officialised, it becomes subject to a set of destructive forces. Career managers who quickly turn the organisation's operational goals into self perpetuation rather than delivering good service. They become entities that are easily targeted by litigation, and become litigation averse, and so easily controlled by corporations with big legal budgets. They are also much more vulnerable to political pressure. When anointed by governments they can be disbanded by those same governments. If it turns out that a particular repressive regime is a right wing despot friendly to the interests of certain large western powers, guess whose operations somehow don't make it to the black lists? There need never be any explicit direction. Just a nod and a wink at the right time to a manager who knows where the power really lies.
Another danger in an official list system is that it would become difficult for most ISPs to not use it. Even if it were provably bad. It might even be mandated by many countries, either directly, or as a necessary mechanism to deflect local litigation. This would entrench a back door for draconian influence by large corporations and politics.
The current anarchic system works because it is not official, not in spite of. Of course the danger is that it can become subject to the personal whim of those in control. Then again, not being an official agency, there is no compulsion to use any given black list. There is an element of market forces here. If a list becomes clearly unstable, pursuing personal vendettas or the like, it will not take long for either, the list to fall out of use, or for second tier filtering of the lists to evolve. Official black lists would be much harder to ignore, even if demonstrably bad.