Low impact refers to how much force travels through your joints, not how hard the session is. You can be completely out of breath without ever leaving the ground.
By removing jumping and pounding, low-impact training lets you train more often with less wear, which is exactly what most people need to stay consistent over months rather than weeks.
Tempo, range of motion, and controlled effort do the heavy lifting. Slow the movement down, own every position, and a joint-friendly session becomes surprisingly demanding.
It is a smart default when you are tired, managing a niggle, or simply want quality work without the recovery cost. Effort stays high; impact stays low.