Biden is not the one doing this (he is not even President). Why do you think President Trump was so ready to get away from the White House? Once the plan was set in place to rescue these little ones, they needed a secure location to bring the children to. The White House is being used as a sort of triage as the children are being brought up. Remember, these children lived in mainly dark areas and are not accustomed to light. People have asked why didn't Trump do it while he was President? He IS now President and is doing this. At first they did not know, but once he did, he pushed forward to having the whole of the area cleared.