First of all, it's super weird to me that so many people, including the NYTimes editors, are summarizing Barr's summary of the Mueller Report by saying some form of "The Mueller Report found no conspiracy with Russia".
Finding not enough evidence to prove something is not the same as finding **that the thing did not happen**. A good dozen people in Trump's orbit committed crimes specifically to hide evidence -- that we know of. Whether it would prove conspiracy or treason or not, there is evidence that has been hidden from Mueller, without which he seems to have wisely *not* found that Trump and his campaign did not treasonously conspire with the Kremlin.
Second, don't we already know that there was a criminal conspiracy in the campaign? We know that there was at least *some* significant knowledge by the campaign about the Kremlin's attacks on the election, and some significant coordination with them. Donald Trump Jr. published very specific evidence of that in his emails, proving that the campaign's inner circle knew about the Kremlin's work to influence the election in Trump's favor, knew that there was dirt the Kremlin had obtained that was likely to disrupt the election, and provided guidance on timing its release.
Further testimony has made it clear that the campaign made a follow up meeting in person with the campaign's inner circle at a time when Trump would be present, that multiple members of the campaign lied about the content of that meeting, and that the campaign promised to consider items at the top of the Kremlin's agenda if Trump won. You don't need to wait for the full report to be released to know that that is collusion.
And when it became clear that the Russians they were communicating with were involved with criminal hacking, it became a criminal conspiracy not to tell the cops about it -- just as has been prosecuted thousands of times for petty crimes.