Earlier quoted context omitted.
If you can't tell the difference between the average LibriVox recording and the average commercial audio book, there is no way you can produce an Audible level of recording. Even if half the volunteering recorders and their gear were as good as those of the commercial offerings, just sitting and selecting those that are not good enough for publishing and those that require some re-recording is a massive extra work.
What is so special about Audible recordings that is unnattainable by Librivox? You mean sound quality? You mean some holy grail vocal mics? Or vocal talent? I don't get it.
I've listened to a few Librevox recordings. They're usually (though not always) tolerable. Occaisionlly good, but that's exceeding rare.
Good audiobooks -- and a friend listens to many -- are far more often vastly superior. Even then, a poor reader is exceedingly grating.
Libravox may improve with time. History of volunteer efforts has been compeling. But not yet.