* Distance: Pluto is incredibly far from the Sun, averaging about 3.67 billion miles away. The further away an object is from another object, the weaker the gravitational force between them.
* Sun's Mass: While the Sun is very massive, its gravitational influence weakens rapidly with distance. This is why objects in the outer solar system experience much less gravitational pull from the Sun compared to those closer in.
To illustrate:
Imagine gravity as a spotlight shining from the Sun. The closer you are to the spotlight, the brighter the light. As you move further away, the light gets dimmer and dimmer. Pluto is so far away that the Sun's gravitational "spotlight" is extremely weak.
Important Note: Even though Pluto experiences weak gravity from the Sun, it still orbits the Sun due to the Sun's immense mass. It's just a much slower and wider orbit than planets closer to the Sun.