Not only that, you can change the behavior of the model as needed.
With 5 finetunes you need to host 5 copies or load and unload them.
With control vectors you can modify the model as needed
With control vectors you can modify the model as needed
If you use LoRA, which many do when fine-tuning nowadays, you don't need five full copies. You only need to store adapters, which can be in the tens of MBs range for a given finetune.