Henryk,
Donald Trump was interviewed for Bob Woodward's book, and Chris Wallace and Jonathon Swan were allowed interviews—no patsies. Trump also did the CNN Town Hall with Caitlin Collins.
Vanity likely played a part, and Trump likes talking.
In contrast, Biden shunned Wallace's invitations for a sit-down and the customary pre-Superbowl interview, likely because of fear of performing poorly.
Best.