>There's plenty of evidence and charges showing that it was

No one was charged with treason or insurrection. A small number had charges of "sedition conspiracy", very few were found guilty of that. You can count them on two hands. I'd have to dig deeper, but I wouldn't be surprised if those were plea deals rather than the government actually proving it.

For the vast majority of the people that the FBI spent a fortune trying to find, it was relatively minor stuff. They didn't even try to burn the building down, unlike the "mostly peaceful" protests that had plagued the country. It's pretty hard to see the witch hunt as anything other than political persecution.