Question

Why is the cell cycle an important process?

Answer 1

the cell cycle is important because if DNA is replicating wrongly or not how it should be, then this is picked up at different checkpoints in the cell cycle and the process is stopped

Answer 2

The cell cycle is necessary for a cell to divide (by mitosis) without that we would never have grown from a single cell (zygote) since that zygote cannot divide without cell cycle. It is also necessary for reproduction (producing sperm or eggs [gametes]), for healing broken tissue growth and development.

The body actually have ways of interrupting the cell cycle in cells that are malfunctioning, it is called programmed cell death (aka apoptosis). This helps stop a lot of cancerous cells before they can become malignant.