Ferroelectric HfO₂ is a promising material for new memory devices, but significant improvement of important properties is necessary to reach applications. However, precedent literature shows that a dilemma between polarization, endurance and retention exists. Since all these properties should be simultaneously high, overcoming this issue is of the highest relevance. Here, we demonstrate that high crystalline quality sub-5 nm Hf_0.5Zr_0.5O₂ capacitors, integrated epitaxially with Si(001), present combined high polarization (2P_r of 27 µC/cm² in the pristine state), endurance (2P_r > 6 µC/cm² after 10¹¹ cycles) and retention (2P_r > 12 µC/cm² extrapolated at 10 years) using same poling conditions (2.5 V). This achievement is demonstrated in films thinner than 5 nm, thus opening bright possibilities in ferroelectric tunnel junctions and other devices.