Mueller could have charged and let the AG determine what to do. It would be clear that he had evidence had he done so, and he would have fulfilled his duty had he possessed evidence to do so.
Mueller also could have simply sat on the case until Trump was out of office. You yourself said that these things can take many years to complete. So what was the hurry if he had evidence?
It is not his job to exonerate or convict.
I was right all along. Mueller was a partisan looking for a way to hurt Trump, and despite 40 million dollars and 2 1/2 years, he found nothing. Everything you see in the Mueller Report is a one sided prosecutors argument without the defense’s responses, and even then, there is nothing.
Mueller had been spurned by Trump for the job of FBI Director just before being named to go,after Trump. He was good friends - both personally and professionally for decades with Comey who was fired by Trump and who wants Trump taken down. An actual “professional” would have declined the appointment for conflict of interest reasons. But instead, Mueller assembled a one sided team..........and he still found nothing to charge.
Mueller also lied to Barr about the OLC not having an impact on his findings.
Mueller “put his thumb and then his whole elbow on the scale of justice yesterday” and in so doing confirmed his bias as an investigator from the beginning (credit Alan Dershowitz for that quote).