The entire solar system precipitated out of the same interstellar dust, which has to contain the remnants of previous generations of stars, including collided neutron stars, in order for there to be heavy elements beyond iron.
We get heavier elements from supernovas, ergo, I don't see how neutron star collisions are a requirement to explain our composition. Citation?
Current belief is many elements can’t be made by supernova and would require neutron star collisions
Not all heavier elements are from supernovae. This is known as nucleosynthesis ( https://en.wikipedia.org/wiki/Nucleosynthesis ) and there are a number of different origins of elements. Exploding massive stars really only get you up to Rb (atomic number 37).