X-Plane 11 is another flight simulator. When
FSX was running the flight simulator market,
X-Plane launched an ultra realistic textured sim with particle physics. Addons were very expensive because making a plane was very difficult, while making planes in
FSX was very easy.
Prepar3d saw this and made a tweaked version of FSX with ultra realistic physics. So
Prepar3d had the advantage of great physics and the simplicity of making addon aircraft. Although it is loved by the Aviation Community FS2020 is going to smash everything.