how come gas and dust can form a galaxy/solar systems/planets but asteroids don’t even form planets or do they but it just take a lot longer?

Question

Might have been asked before but got bit high and started wondering random stuff haha

In: Physics

Answer 1

But asteroids that hit planets do become part of those planets… The same is true when they hit moons.

This is assuming they aren’t big enough and fast enough to destroy the planet.