We have to distinguish between the typical deviation from the "nominal value" of a oscillator (due to production issues) and the actual behavior in your environment, the latter is heavily influenced by temperature, PCB layout, choice of capacitors, and, and.....
Both effects are rarely separated in non-expert dicussions. To get the best out of a crystal oscillator you definitely need a temperature compensation (often done by a "heating" resistor to keep it warm) and a trim capacitor to tune to the requested frequency....