You think space X grid fins are air brakes. You completely made that up and still refuse to provide any source. You never will.
Falcon 9’s is equipped with hypersonic grid fins which manipulate the direction of the stage’s lift during reentry.
they control roll, pitch, and yaw the 14-story stage up to 20 degrees in order to target a precision landing.
Falcon 9 Grid Fins do not work as brakes & they are not designed with increase drag either.
That is absurd nonsense because if they designed them with any drag beyond that which is needed to control roll, pitch, and yaw the Grid Fins will simply rip off in reentry & likely tear the vehicle apart in the process.
They cannot be used as airbrakes & must have reduced drag to offset the immensely compressed & superheated airflow of reentry & hypersonic flight. SpaceX
Lastly, The Falcon 9 stands 229.6 feet tall and has a mass of 1.2 million pounds…
You are out of your mind if you think those 4 Grid Fins are slowing it down in reentry.