> at these speeds, over 20000km/h, the falling debris will travel a very long way before coming down.

Without air resistance, falling 145 km takes 172 seconds, which would result in the debris falling 956 km east of the explosion point if it were moving horizontal to the ground to begin with. With air resistance, it is substantially shorter as everything is decelerating proportional to the velocity cubed. If we approximate the terminal velocity of the debris as 500 km/h, to a first order approximation it would travel approximately 79 km east. The distance from West Caicos island to Grand Turk island is 138 km, for reference.

Satellites are moving much faster and at much higher altitude. Starship was not in orbit.