I never expected there to be enough evidence of full-on conspiracy, but the investigation is one way to start exposing Trump's venal, corrupt character and the bullshit bogus facade of himself that he is constantly propping up. It's no less a political attack than just about every imbecilic thing that comes out of his mouth or that he tweets.
He's going to crow, boast, strut, preen, tweet his heart out, pound his chest. It will almost make you throw up. "No evidence" is a hyperbolic assertion, especially when the only summary of the report comes from the Trump administration's DOJ. "The opinion of Trump's AG", who prior to being confirmed had been extremely critical of Mueller's investigation. Nothing for violating the emoluments clause, tax fraud, campaign finance violations, illegal use of inaugural fund .. etc.
One of the concerns I've had in the era of Trump is the potential for people to reach the conclusion that there's no way to know the truth, and that it's just politics as usual.