For starters, you are just flat out wrong. Straight from the horse's mouth.
Secondly, maybe you didn't realize that unredacted pages of the Mueller report were released related to Trump, Jr.? I guess MSNBC didn't report that. Just so you wouldn't have a complaint about the source, I have linked to the pages themselves along with an article from no so right-wing Yahoo referencing to the unredacted pages that were released in response to the Freedom of Information Act. Keep in mind, even though these pages were focused on Trump, Jr. they state that there was not sufficient(insufficient) evidence to support criminal charges against the Trump campaign. That includes Donald Trump himself as he was most certainly part of the campaign.
Second, while the investigation identified numerous links between individuals with ties to the Russian government and individuals associated with the Trump Campaign, the evidence was not sufficient to support criminal charges. Among other things, the evidence was not sufficient to charge any Campaign official as an unregistered agent of the Russian government or other Russian principal. And our evidence about the June 9, 2016 meeting and WikiLeaks’s releases of hacked materials was not sufficient to charge a criminal campaign-finance violation. Further, the evidence was not sufficient to charge that any member of the Trump Campaign conspired with representatives of the Russian government to interfere in the 2016 election.
DocumentCloud
A New Version Of The Mueller Report Reveals That Mueller Declined To Charge Donald Trump Jr. And Roger Stone With Computer Crimes