I just happened on this thread and its interesting to me. I think the correct answer is “evolving” as all good projects should and IMHO the best “metadata system” in existence, but needs to keep evolving (which they are doing).
I have been watching MusicBrainz for over 10 years now and it was only 2 years ago that I started to actually use it, and a year ago that I got my account. I am album centrist not recording centrist and my workflow reflects this. I have gone through many disappointments in the last 15 years over the state of music metadata as I do not like to repeat work already done. Catalog programs, rippers, taggers, and other components have come and gone over the years. Much depends on what you are needs or wants are. Many people are happy to just play their music and get a title and artist displayed.
What scares me is the lose of free public access to all forms of the metadata as we witnessed with the original CDDB becoming Gracenote. As I have watched the internet and its “products” over the past 20 years its is clear the once available information has been put out of reach except for payment by unit or subscription. This is not necessarily bad as someone has to pay for the costs of providing the information, which gets us into ownership of that information which can be a sticky subject. Just remember once that information is removed from the public getting access to that information can be out of your control. I have somewhat digressed off the main subject line but thought it would be helpful to the topic.
Does MusicBrainz need to do better? Absolutely, but that is up to the community to push for, and we all need to help. How easy or how difficult it is to use the interfaces into MusicBrainz is left to the user to decide and each of us have own own strengths and weaknesses. I am dyslexic and entering data at the keyboard is a very risky thing for me so I do all my processing off line and generate lists of data to cut and past. I find Picard difficult and would rather a batching type system that did not have so many manual user checks in your way, but I have found they are truly necessity in order to keep duplication and and errors to a minimum. The information needs to be accurate.
I could say much more, but that’s for another time, time for me to turn “-v” off.