Because you have to consider all the court appointments he made, including the supreme court that he stacked. If the Biden admin did any more, itd just get struck down. The court can basically nullify any law or executive order they want without repercussion. Im frankly shocked he got away with as much as he did
He could, but traditionally the court is suppoaed to have seven Justices. He respects that did not want to be seen as trying to stack it. Unfortunately Republicans have no intention of giving the slightest fuck, were already stacking the court, and will likely continue doing so. If you ask me, I think Biden shouldve stacked it