First, I don't think he's some intellectual guy (even in 2008) who sat and read intelligence documents like this. In fact...I doubt if Trump, Obama, Bush, Clinton, Ford, Bush or Carter sat around and read stuff like this.
Second, I think this stuff got mentioned....with some aide (helper) who requested it to be brought to the White House, and the documents sat around in some bookcase for the most part.
Third, I think as the 'boys' packed up.....they shipped various classified materials off....to the Biden-Center or this garage in Delaware.
Fourth, you could probably visit Obama's library and find 200 classified documents like this.
Is it poor security? If you were in the Navy or Air Force....you'd be charged up, and spend at least a month or two in some jail....for just one single document.
If it was shipped like Trump did it....to a SCIF room? Well....it's all legal. But in Biden's case....no, none of the two spaces were a SCIF.