Or more, logically, if there was nothing there, why did it take so long? Remember that Mueller is only an investigator, and he used indictments as an investigative tool; once he had all the information he needed, even if they were crimes, it wasn't his place to indict, that will be up to the new AG. The Justice Department also has a policy of not indicting a sitting president. It may be anticlimactic, but don't forget Mueller handed down 37 indictments, multiple plea bargains, and convicted Trump's campaign manager at trial. That by itself is historical, even if we are a bit numb to it all, by the drip-drip nature of the process.