Ah, no. The only reason Cohen was investigated was because of the Mueller investigation. Indictment on those "unrelated crimes", puts Cohen in a vulnerable position, and helped illicit his cooperation with federal investigators. Now mueller moved another piece on the chess board in securing his plea, putting Cohen back in his court, and naming "individual 1", as Donald Trump.
If you don't think there is more going on here, I think you're fooling yourself. You're certainly not fooling me.
Obstruction is a serious crime.
Perjury is a serious crime.
Both are felonies, and may result in Orange Jumpsuits.
You do realize that obstruction is a crime, and it's about obstruction and intent, an ongoing investigation, and your idea that "but Trump was innocent" is meaningless in this context, right?
Do you understand that white collar crimes of conspiracy/corruption are very difficult to prove because it's all hidden, often within the tight ranks of people who are all incentivized to deny, deflect, and destroy accusations/evidence? If obstruction was not a crime, they could get away with anything, just order it to stop, it's stopped. case closed. You have to understand how incredible terrible that would be, and the corruption it would quickly lead to.