Or, if you want to cut right to the chase, Schoenfeld says:
With respect to hypertrophy, the compelling body of literature indicates that similar whole muscle growth (i.e., muscle thickness, CSA) can be achieved across a wide spectrum of loading ranges ≥ ~30% 1RM. These findings are independent of age and training status. Thus, as a matter of principle, there is no ideal “hypertrophy zone.”
So train how you like. If you’re working close to failure, you’ll encourage your muscles to grow. And that can be done with resistance bands, free weights, machines, or a gallon milk jug.