I will review the recent progresses that our team has made using Gaia DR3 data. It includes the detection of a significant (Keplerian) decrease for the rotation curve of our Galaxy, and the fact that most Milky Way dwarfs are newcomers in the halo (as we already know for the Magellanic Clouds). Both discoveries lead to a considerable, downwards revision of the dynamical masses of Local Group galaxies, which will be presented. Finally, I’ll discuss possible consequences on cosmological models, as well as new observational hints that constrain the mass of dwarf irregular galaxies, such as WLM and the Large Magellanic Cloud.