One reason Biden has been able to stall on holding his first presser until now is because his message discipline has defused the drama created by the Covid-19 pandemic and the trillions of dollars in relief. The Biden people have their point and stick to it.
The Trump administration leaked so copiously because he had assembled not a team of rivals to serve under him but a team of enemies, who used the press to fight their policy battles and wage psychological warfare on each other in public. For example, the Javanka faction in his White House advanced a personal PR agenda separate from the president’s, and their White House enemies were forever leaking information about the power couple to disable them. Biden, who has no analogous warring factions, has had an easier time keeping the peace.
Trump both craved and reveled in these internal death matches, something you can’t imagine Biden doing. Trump was forever calling his kitchen cabinet of corporate titans and irregulars like Steve Bannon, Roger Stone, Rudy Giuliani and Sean Hannity for advice and gossip, and those conversations tended to leak. Biden, on the other hand, tends not to go off-site for counsel; his closest advisers have been the same people for decades, and they’re installed physically close to him in the West Wing. With fewer people in fewer places tasting the unadulterated Biden, less gossip flows to reporters. Finally, Trump was notorious for not keeping up on his reading. If an aide wanted to direct his attention to some issue, often the best way to do so was to get it to his boss on TV, leaking the material to reporters so Trump would see it on cable news. This put Trump on both the supply and the demand sides for leaks.