MOSAIC will characterise gaseous outflows in large samples of active galactic nuclei (AGN) over cosmic time and with a wide range of luminosities. The unique spectroscopic capabilities of the instrument, further enhanced by adaptive optics corrections, will allow us to map in detail the outflows of ionised and neutral gas, including their kinetic energies and mass outflow rates, and to constrain their extent and geometries. Such a comprehensive census will finally provide a self-consistent picture of the impact of SMBH-driven outflows on the regulation of star formation in galaxies.