ORIGINAL: FenderBean
After 25 years I have never lost anything due to power loss from overloading my setup.
Well, now that you are into jets I guess it's time to think about it.
The interesting thing about this hobby is that our airframes push the servos and electrical system available on the market to their limit. Understanding how all of this work and being able to characterize your requirements will save you a lot of hassle and make your plane much safer.
It is not just a "cool" stuff. The purpose is to increase safety and predictability.