We had the motive. We had the means. oh yea, and our president said we would do it in advance of it happening:
"If Russia invades, that means tanks or troops crossing the border of Ukraine again, then there will be no longer a Nord Stream 2. We will bring an end to it." (reporter: "How will you do that, exactly, since the project is within germany's control?") "I promise you we'll be able to do it. (smirks, silence)"
https://youtu.be/OS4O8rGRLf8?t=81
With that context why wouldn't the default be to assume it was destroyed by the US unless there was compelling evidence otherwise?
As CIA guy I would not trust Biden to keep the mouth shut.