Orbit and meteors

Some do. Meteors are subject to the same laws that define the orbits of moons and planets.

Rap

Meteors do fall into the Sun and Earth and all the other planets. That's how the solar system was formed, orbital debris (meteors and asteroids) fell into gravitational wells and got stuck, forming the stars and planets.

The asteroids we are left with today are simply those which did not contribute to the formation of the Sun and other bodies (planets and moons) because they were in relatively stable orbits (and still are).