I think of it like "magnets as rubber bands", and what I call "Feynman lies":
> I can't explain [magnetic] attraction in terms of anything else that's familiar to you. For example, if we’d said the magnets attract like as if they were connected by rubber bands, I would be cheating you. Because they're not connected by rubber bands, I shouldn’t be in trouble, you’d soon ask me about the nature of the bands… and secondly if you were curious enough, you'd ask me why rubber bands tend to pull back together again, and I would end up explaining that in terms of electrical forces, which are the very things that I'm trying to use the rubber bands to explain, so I have cheated very badly, you see.
> [...]
> But I really can't do a good job, any job, of explaining magnetic force in terms of something else that you're more familiar with, because I don’t understand them in terms of anything else that you are more familiar with.
direct link: https://www.youtube.com/watch?v=nYg6jzotiAc&t=1263s
but the whole chapter is worth a watch: https://www.youtube.com/watch?v=nYg6jzotiAc&t=894
I think you're misremembering, we don't know what's at the center of a neutron star, or that there aren't other, more dense, types of stars.
That’s what I get for treating modern physics as a kind of a vaudeville show ;)
Black holes and neutron stars are fundamentally different - there’s no space left between the matter of a neutron star. Now, the physics of that is a bit over my head, but a simplification I got from a PBS Spacetime episode is that the matter in a neutron star pretty much overlaps in 3d and stars filling up some quantum mechanics dimensions. When those cross a threshold, the last forces give way and everything collapses without a limit. So now we’re talking about a ball on your cellophane as small as physically possible for its mass (compact), pushing down significantly deeper… Until it gets replaced with pretty much a puncture, pushing it down to some abstract floor.