It is hotter closer to the, so the proto-planets cannot capture H and He gas. Form rocky terrestrial planets with few ices. Planets with the biggest cores grow rapidly in size, increasing the amount of gas accretion. Gravity of the proto-Jupiter keeps the planetesimals in the main belt stirred up. Never get to aggregate into a larger bodies.
Ices condense very quickly onto rocky cores.
Stay small because of a lack of material. Disperses the rest into the Kuiper Belt to become Kuiper Belt Objects. Comets and other Trans-Neptunian objects are the leftover icy planetesimals from the formation of the Solar System. The whole planetary assembly process probably took about 100 Million years. Light from the Sun dispersed the remaining gas in the Solar Nebula gas into the interstellar medium.