Asking if it was a failure is a stupid question. Mueller did the job he was set out to do and this report documents that fact, which no one can argue wasn’t extensive and detailed. So if that’s the metric we’re using, than it’s clear it was a huge success?
What your getting at is a mucky world of spin and media expectations, which you perhaps unwittingly play in to with the title of your article. Was Mueller’s report a failure? Well if enough media outlets have that as their title than viewers will start to think that, regardless of what’s in the report.
My point is that the question is stupid. Mueller did what he was set out to do. Trump did some sketchy things at the very LEAST, and media needs to stop trying to influence the audience before they even get to the meat of the subject at hand.