Matter is made up of atoms. The interesting thing about an atom is that most of its mass is concentrated at the center, in the nucleus. A nucleus is orbited by electrons. These electrons have very large orbits. Electrons need large orbits because they exhibit wave nature and a wave is comprised of crests and troughs. Also, each electron’s position is spread over an orbital and has a range of probabilities. The emptiness of an atom really benefits the electrons as a lot of free space is available for the free movement of electrons.
If we were to, hypothetically, condense all atoms, by removing the empty spaces in them, the entire human population would be downsized to the size of a sugar cube. The sugar cube would be very heavy and it might not even have the same physical properties that a regular sugar cube has. But this is an interesting analogy to understand the vastness of the empty space in each atom.