As John M. Powell explains in the video, the Chinese balloon is likely above 100 thousand feet above sea level. No plane with bullets can reach that high. Even if a fighter jet could send bullets through the balloon, the bullet holes are small and would take hours and probably days to down the balloon and its package. By then the balloon could be over Chinese territory again.
A missile may not be able to spot the tiny radar signature of the balloon, and if a missle exploded the balloon cargo, the resultant debris would be difficult to gather and take a long time to analyze. JP’s four decades plus of rocketry and balloon experiments provides an authoritative voice for all things traveling the skies. More videos at http://www.jpaerospace.com. Click on the Menu to find Videos.