the steeper the slope—the bigger the mass at the bottom of the gravity well?
There are 4 established natural forces, gravity, electromagnetic, weak nuclear, strong nuclear. Gravity is not alone.
Also, maybe mass doesn’t cause gravity on its own, maybe gravity is the result of mass’s interaction with something else- that causes a distortion in space, which we call gravity.
Gravity waves exist…how does that happen? (I think some causes are known.)