It would be a waste of money unless you have a specific reason for doing it. A 1TB SSD runs about $200. A 4TB WD purple runs about $150. SSD has a limited writing lifespan, when you hit that limit, it becomes read only.
The Pros of SSD over a HD is they are fast and don't consume a lot of power. Neither of which normally matter in an NVR.
The Cons of SSD over a HD is they are expensive, and don't have high capacity. Normally you want as much storage as you can afford in an NVR.
I'd stick with surveillance drives unless someone is giving you a stack of free SSD drives. And even then, your NVR probably only has 2 SATA ports.