Again, a special prosecutor has already said that while Biden may be guilty (may), that he turned down prosecuting him because he would be "seen as a nice old man with a poor memory"...Biden was not pardoned. Several others you claimed committed crimes were not pardoned.
So, you are asking "why" to a question that already has an answer.
As far as "several others"... you need to be more specific. Names, what crimes you think they should have been prosecuted for, etc. ... at this point, you are playing "gotcha" with a spent hand.