Technically he was, he was acquitted. In order to be exonerated you need to be convicted of a crime, then have that conviction overturned. But since they can't charge him with a crime, let alone convict him, he's acquitted
How many times do we need to repost Mueller's conclusion that there was no Russian cooperation. All their attempted intel traps and meeting setups was to make a case and the suggestion he was conspiring, it was all smoke to start an investigation in the hope to get him on an obstruction impeachment charge. And that's a big part of what Durham is looking at, why did the persist with the Russia crap into his Presidency when they knew so early on it was BS. If the FISA's were invalid, then everything built on top of that thereafter (Mueller) is highly highly illegal.
Every single one of the 29 FISA's they had on people around him has now been proven to be illegal, meaning there was no FBI evidence to support the validity of any of the claims in the warrants