Some monitors are roughly calibrated to Gamma 2.2 at the factory (e.g. Eizo). However, the monitor must still be recalibrated every 200 hours and the profile must then also be validated (sRGB, Adobe RGB, etc.). Depending on this, you also need different targets regarding white point (5000K, 5500K, 6500K), brightness (80 cdm, 100 cdm, 120 cdm) and gamma 1.8 or 2.2.

You see... A factory calibration is of no use at all!