5G promises a more Internet of Things-friendly ecosystem with vast improvements over the current capabilities of 4G. The benefits of 5G include ultra-low latency (less than one millisecond) and greater density (up to 100 times more connected devices per unit area) and better network energy usage. The downside is that the risks involved from a cyber perspective tend to grow exponentially in these scenarios; when controlling your car on the freeway, performing remote surgery or providing power to cities, cyberattacks can literally become a matter of life or death.
Source: https://threatpost.com/5g-and-iot-how-to-approach-the-security-implications/148681/