True, there is a high degree of standardization to electric motors. Unfortunately, it’s this kind of standardization:

Individual motors might be a standardized part class, for easy switching out… but there’s a lot of different organizations running around with their own needs and goals, so even within highly-specific categories of operation, there’s still a lot of differences.
The wikipedia page notes 14 different categories of electric motors, which themselves come in different sizes, depending on the specific device they are intended to power. The electric motor in a toothbrush is different from that in a blender, despite the fact that you might call both ‘tiny electric motors’ since they both have fairly minimal power and can’t move you around. Similarly, the motor of of a lawnmower is different from that of a scooter, since the former needs an awful lot more torque; and so on. The size of the motor makes for a good general distinction, but there’s certainly room to subdivide the motors down further to any degree of granularity you like.