On the contrary Musket, we see galaxies in very close proximity, we see them merging, we se them stripping bits off each other due to tidal forces, we see them stripping gas out of each other, we see them accreting gas from the spaces between them. But the spaces between the stars are vast compared with the sizes of the stars themselves (as you can see by looking up, apart from the sun we can resolve no star except by combining the signals from telescopes as an interferometer). So two galaxies can pass right through each other and no stars will hit. They will slow each other down though due to dynamical friction.