>

I'm sure Bush is nervously looking over at his filing cabinet.
Voluntarily returned vs refused to return. 
Do the math. >

Also "Classified" vs. "TS/SCI source documents." >

They were discovered by his own attorney. He was the one that notified The National Archives. They promptly returned them.
It seems like there was nothing particularly sensitive there. 
And I guarantee Biden hasn't seen these documents in ages. They were in a box, in his garage, in his former residence. 
Trump had his sensitive top secret documents in his personal possession. In his safe and scattered around his office.  Was asked for over a year to return them to the federal government. Refused to the point that criminal investigators needed to get involved. 
It's not even close to the same thing. >

All this tells me is that there are likely hundreds of top secret documents floating around in random boxes and filing cabinets. I assume this is rather common. Trumps guilt comes from the fact he hid them, refused to return them, likely and stole them to sell.