Both spotting scopes and binoculars serve different purposes. It always depends on the kind of activity that they will be used for that makes it easier to choose between spotting scopes and binoculars.
For wildlife viewing and bird watching trips that involve mobility, binoculars are the better choice. With two lenses and two eyepieces, binoculars are compact, shorter in size and can be hung around the neck. Further, binoculars tend to be stronger and survive falls better. A good magnification also helps to see animals that are located at medium to long distance.
Spotting scopes, on the other hand, have higher magnification than many binoculars although some high-end binoculars have the same magnification as low-end spotting scopes. They tend to be taller and heavier in size and therefore usually require to be adjusted on a tripod if viewing for longer hours. Spotting scopes are best used if you are intending to sit for a long time and if you wish to perform extremely long-distance viewing.