If you looked at the districts / states where the has a big ground and ad game, those places performed a percent or two better than the places they didn’t campaign in.
The ground game worked, but the broader national message and messaging strategy didn’t work as well as the republican’s. In places where there was no aggressive campaign spend from the GOP or DNC, the Dems often underperformed by an extra percent or two.
Maybe it’s the new media landscape that the GOP is so good at controlling, or maybe the Dems core message wasn’t strong enough, or maybe it was because Harris had to do what Trump had been campaigning on for 4 years, or maybe people are hurting and think the grass will be greener. People will probably debate this shit for decades.
But, IMHO, the media and ground game did quantifiably move the numbers in Harris’ favor. But she was down by 3% or 4% and only clawed back 1 or 2 with media.