I am posting this answer here because the duplicate question that I was originally Writing for was closed as duplicate:

Why light can't escape a black hole but can escape a star with same mass?

For the purpose of this question as posed I will use a neutron star before and after collapse.

There are really nice answers (I am referring to the original question) by @nielsnielsen and @Jerryschirmer, I feel like I need to add this answer because the explanations though perfectly correct, do not explain some very important points about gravity being very special:

1. Gravity creates more gravity and is always attractive, this can be said in many ways, like gravity is self interacting or gravitons emit gravitons or that curvature possesses energy and thus creates more energy, but the important thing to understand is that gravity is able to “build” large objects where (like in a neutron star) after a certain limit gravity can overcome the other forces and become dominant, crushing the object and compacting it into a smaller and smaller region of space while the effects of gravity can grow limitless.

2. The distance from the object does matter but in a non-trivial way. You are saying that the gravity of the star before and after collapse is the same but this is not completely correct. What is correct is that far away from the objects the effects of gravity can be felt the same way regardless before and after the collapse. But as you get closer to the objects this becomes more complicated and the answer is the (qualitative and quantitative difference in) structure of spacetime around the two objects and how their mass (in reality stress-energy content) is allocated in space.

Very naively saying, at the surface of the neutron star the full energy content of the star is affecting you in an attractive way towards the center of mass, and hovering at the EH of the black hole, same is true, and assuming same energy content, we should feel the same effects. But as you see from the answers, the escape velocity (which is just one way of expressing the effects of gravity) does depend on the compactness of the object. But why? I believe this question is asking deeper into this explanation and the answer lies in the description of gravity as the only known force being able to overcome the other forces and compress the energy content into ever smaller volumes of space. This, together with the fact that gravity is self interacting (always attractive) and that spacetime curvature itself has energy and thus creates more curvature gives you the real answer what happens when gravity compresses the energy content of the neutron star into and ever smaller region. The qualitative difference lies in the fact that in the case of the neutron star the energy content (and curvature) is spread over a larger volume of space combined with the fact that gravity is self interacting. Imagine all the particles in the star curving spacetime around you themselves, but are spread out in space and cannot overlap and constructively interfere (self interact) as they do In the black hole. If the energy content is compressed(in the black hole) the particles simply get closer, increasing the self interaction of gravity, and this effect can grow limitless and leads to an event horizon.

Remember distance matters when dealing with gravity but not only for large objects, but for elementary particles that make them up too, if the particles are closer, their gravitational effects are stronger (relative to when they are spread out) and can create extreme spacetime structures. This is the ultimate answer to your question. This can create the extreme effect of an event horizon.

I am posting this answer here because the duplicate question that I was originally Writing for was closed as duplicate:

Why light can't escape a black hole but can escape a star with same mass?

For the purpose of this question as posed I will use a neutron star before and after collapse.

There are really nice answers (I am referring to the original question) by @nielsnielsen and @Jerryschirmer, I feel like I need to add this answer because the explanations though perfectly correct, do not explain some very important points about gravity being very special:

1. Gravity creates more gravity and is always attractive, this can be said in many ways, like gravity is self interacting or gravitons emit gravitons or that curvature possesses energy and thus creates more energy, but the important thing to understand is that gravity is able to “build” large objects where (like in a neutron star) after a certain limit gravity can overcome the other forces and become dominant, crushing the object and compacting it into a smaller and smaller region of space while the effects of gravity can grow limitless.

2. The distance from the object does matter but in a non-trivial way. You are saying that the gravity of the star before and after collapse is the same but this is not completely correct. What is correct is that far away from the objects the effects of gravity can be felt the same way regardless before and after the collapse. But as you get closer to the objects this becomes more complicated and the answer is the (qualitative and quantitative difference in) structure of spacetime around the two objects and how their mass (in reality stress-energy content) is allocated in space.

Very naively saying, at the surface of the neutron star the full energy content of the star is affecting you in an attractive way towards the center of mass, and hovering at the EH of the black hole, same is true, and assuming same energy content, we should feel the same effects. But as you see from the answers, the escape velocity (which is just one way of expressing the effects of gravity) does depend on the compactness of the object. But why? I believe this question is asking deeper into this explanation and the answer lies in the description of gravity as the only known force being able to overcome the other forces and compress the energy content into ever smaller volumes of space. This, together with the fact that gravity is self interacting (always attractive) and that spacetime curvature itself has energy and thus creates more curvature gives you the real answer what happens when gravity compresses the energy content of the neutron star into and ever smaller region. The qualitative difference lies in the fact that in the case of the neutron star the energy content (and curvature) is spread over a larger volume of space combined with the fact that gravity is self interacting. Imagine all the particles in the star curving spacetime around themselves, but are spread out in space and (the effects of curvature) cannot overlap and constructively interfere (self interact) as powerfully as they do in case of the black hole. If the energy content is compressed(in the black hole) the particles simply get closer, increasing the self interaction of gravity, and this effect can grow limitless and leads to an event horizon.

Remember distance matters when dealing with gravity but not only for large objects, but for elementary particles that make them up too, if the particles are closer, their gravitational effects are stronger (relative to when they are spread out) and can create extreme spacetime structures. This is the ultimate answer to your question. This can create the extreme effect of an event horizon.