Here is a bit of information of the use of elastic bands in training!
Performed correctly and programmed appropriately, bands can be a useful tool when training to improve a particular lift. "Elastic bands can challenge or assist the human strength curve by providing variation in how a muscle complex is challenged over a range of motion" - Wilson et al
Very simply, a "strength curve" (SC) describes the amount of force a muscle, or group of muscles, can produce within a given range of motion (ROM). Different positions within a movement will require differing levels of force production. E.G. With the bench press - maximum torque is generated when the elbow is flexed. The force requirement is higher, as the joint is in a less advantageous position. Compare that to when the elbow is more extended, the force requirement is less as the elbow is in a more advantageous position. This is called an ascending strength curve.
However, with the ever increasing tension of the band, you can develop the strength curve of an athlete. In the case of an ascending strength curve (ASC), as the joint extends, the band will extend with it, increasing the tension and increasing the force requirement. This is a great way to develop athletes who perhaps struggle with the lock out in movements such a bench pressing, Squatting and Deadlifting. Bands can also assist in the development of these movements if the athlete struggles with the "sticking point" (bottom of the movement or when the joint angle is highest) by unloading the bottom position with band assistance.
Power and rate of force development has also been shown to improve via training with bands. A study by Matthew R et al concluded that peak force, power and rate of force development can all be improved via elastic band training.
So benefits are:
1️) Improves strength curve
2️) Accentuates weakest position within movements (bottom of squat for example)
3️) Shown to improve RFD and power
4️) Unlike other loading modalities like chains, they work in a multiple of planes
It is important to note however that a training programme shouldn't just rely on bands for resistance. The bottom positions of movements such as the Squat & Bench Press need to be developed. Very often it's not the lock out that people need work with, it's the "hole".
It all comes down to you as an individual. You must evaluate your lifts, assess where you are weakest within those lifts and develop them. You must perform a needs analysis and a gap analysis in order to make your training interventions appropriate. Don't just throw in banded training (or any other type of training) for no justified reason.
If you have any questions regarding this subject, then please let me know.