@_auroraborealis_ nailed it with the “why is DVC busy if the parks are dead” piece, the flip side is “why are the parks dead if DVC is so fully booked?”.
Here’s why: DVC rooms in total have a capacity of approximately 35,000 guests at WDW and that’s counting all the cabins; in reality the rooms are probably holding 20,000-25,000 guests.
MK and Epcot
each have daily capacities approaching 100,000 guests, and between AK, DHS, two water parks, DS, WWoS, various golf and mini golf activities, that’s another 100,000+, and that doesn’t even consider all the things you can do in Orlando that aren’t WDW, like Universal, or playing frogger downtown with the worst drivers in the country.
So DVC guests take up less than 10% of total park capacity. They don’t make huge impact.