I've read that string theory suggests that black holes may be stringy fuzzballs without a singularity at the center. Instead, strings pile up all the way to the event horizon. My understanding of non-stringy black holes is that the gravitational compressive force overcomes all known repulsive forces (such as electrostatic repulsion between particles) and so the compressed matter collapses with nothing stopping an indefinitely denser collapse, resulting in a sigularity at the black hole center. Now the fuzzball conjecture posits a stringy ball that extends to the event horizon. My question is, why don't the strings collapse to a singularity, just like non-stringy matter does? Don't the strings have the same mass and gravitational effect as their non-stringy counterpart-particles (eg - a neutron represented by a string, or as a particle/wave, still has the same mass and gravitational attraction)? Don't stringy particles have the same repulsive forces as their non-stringy counterparts? What allows a fuzzball to build matter to the event horizon without collapse?