So true. Sometimes there's a person behind the scenes keeping it all working with bailing wire and elbow grease, but that person is also a huge point of failure.
Diffuse is different from distributed.
In distributed responsibility, there is redundancy. Multiple people ensure things operate. This is good.
In diffuse responsibilty, people cancel each other out, so it's worse than having one person.
An office version of the bystander effect, if you will.
This is particularly bad in volunteer organisations, where wishes and reality do not mix well.
Single point of failure is in important thing.
So I've seen people try to convert a SPOF system, where one or two people are keeping the business and systems running, to a diffused responsibility system.
With the result that one or two people still keep the business running... out of exasperated necessity.
But with more complaining by others, because that's not supposed to happen.
If it were complaining by others that more people aren't taking up meaningful responsibility and doing the work, that makes sense to me. But it's usually complaining by others about the people doing the work. And since they are volunteers, that's a shitty position to be in.
Complaints include that they aren't "letting" others do it. Which couldn't be further from the truth.
People keep being asked to help, and keep being individually not very available. Or, worse, available in not really useful way (impractical hours for example, or sessions too short), or on balance unhelpful.
Those few being meaningfully responsible are, however, not "letting" others access critical databases such as personal data, and safety critical systems, without building up a trust reservoir and track record first, and in some cases formalised relationships. And that seems to make would-be volunteers rather grumbly, in a public way.
At least in volunteer organisations, the bottom line is most people avoid work if they think they can rationalise why it shouldn't need to be done, will gut requirements and constraints, if they don't personally like them, and will avoid taking initiatives on things they think are stalled, if they can get away with portraying it as someone else's fault.
In short, they are contradictory, wanting thing to happen, but rarely taking actions that lead to it.
That doesn't match what actually needs to be done, so it falls on the same few shoulders again and again, and usually at crunch times, as those shoulders are criticised if they take action too early.
Then we end up with "hidden single point of failure", which may be worse than the visible kind.