Wake up! The Mueller report is consistent with Barr’s characterization you cite and quote to in your post.
Barr's characterization wasn't actually a characterization. It was a seriously politically motivated abbreviated overview of the two primary objectives of the investigation, which in general, should lead to a characterization of a report, except in this case, where Mueller says Trump dun fucked up on abuse of powers... but a conviction
in court would be very hard because he must prove intent of Trump... and most of the people who were ordered to obstruct justice either refused to comply or refused to testify due to fear of self-incrimination.
Mueller's Report says, in quite a few more words, 'It would be very hard for me to convict on these charges, but Congress should impeach Trump.'
That is the accurate characterization of the Mueller Report. Barr's initial report on the Mueller Report was, maybe not a "lie", but I think "complete bullshit" could accurately characterize his initial public assessment.