When training muscles, if the muscles adapt to a certain weight at present, if the weight they bear exceeds the adaptive weight, the muscles will be forced to become stronger and more developed to adapt to the increased load. With the passage of time, gradually improve the muscle circumference.
Later, if the muscles adapt to the resistance of elastic belt in most movements, the difficulty of training movements will be lower and the repetition of movements will be higher. It is more about training endurance than increasing muscle circumference, and the effect of increasing muscle is very insignificant.
To sum up, whether elastic rope plus self-weight training is useful depends on your training objectives. If you pursue health and initial muscle circumference, you can! If you pursue muscle gain and large girth, it is recommended to use it in the early stage and replace it in the later stage.