Trainees often ask which is better, supersetting two different exercise for the same muscle or simply grabbing a lighter weight and continuing to rep out on the same exercise—a drop set. Each has its own unique benefits.
In other words, one is not “better” than the other; they are just different. Both are excellent methods of getting a longer tension time on the target muscle; however, with supersets you get a slightly different angle of pull by using another exercise. That can be both good and not so good.
A different angle of pull means you involve different muscle fibers; however, the fibers that were forced to work on the first exercise may now have a disadvantageous leverage. That means the stress will be less on those particular fibers.
Is that something to worry about? Not really. If the gym isn’t crowded and you can superset, do it. If there are too many people hogging equipment, use drop sets. Either method will up your tension time, get the blood flowing and the target muscle growing.