Found:
That the Russian government funded efforts to subvert the 2016 election to help Donald Trump win.
That multiple Trump campaign and/or inner circle associates met with Russian operatives who were offering to help the Trump campaign. That most of those encounters were not reported as required and in many cases the Trump associate initially lied to investigators.
That the investigations were unable to talk to Key participants or review key documents because of direct obstruction by Trump and his administration. As such they were not able to Recommend anymore indictments than the many that did come out of them.
The Mueller report stated that other Trump associates could at least make a case that they didn’t understand what they were doing was wrong. See Donald Junior which is a veiled way of saying too stupid to waste time with.No matter how many times he lied.
But the Mueller report recommended a number of indictments, and specifically called on Congress to pursue 10 potential incidents of obstruction by the president, and pursue the witnesses and other evidence that the Mueller investigators were obstructed from.

But Barr and the republicans squashed it