In our Solar System, planets, dwarf planets, asteroids, space dust together hold 0.15% mass. The rest of the 99.85% mass is held by the Sun. I think this mass d

In our Solar System, planets, dwarf planets, asteroids, space dust together hold 0.15% mass. The rest of the 99.85% mass is held by the Sun. I think this mass distribution is uniformly true for other stellar systems as well, where majority of the mass is held by the stars (singular, binary, collapsed) and very small amount by other objects in the system. Given the above, why is there so much postulated "dark matter"?