It could even be setting you up for injury if you have muscle imbalances.

The idea is not to increase intensity, but to challenge your body by forcing it to recover more quickly.

When the body is doing a set rhythm, it expends less energy than when it's forced into multiple movements.

The whole gym environment, especially if it's machine-based, focuses on very fixed, linear-path movements, but the body doesn't really work that way in real life.