5G is not just faster data and/or higher capacity only. It is much more than these obvious characteristics.
For one thing for IoT to succeed; the grand vision created for its debut on a universal scale, 5G is a must. More users; more devices interconnected at any instant of time. The 5G must address the issues arising out of interconnected devices in addition to only users. Also for IoT to succeed additional items like coverage of the serviced region (Can you hear me now!) and more efficient networks.
The data rates required by 5G are some 1000 times that provided by 4G to make things happen with low latency. One immediate challenge is the unavailability of spectrum (700 MHZ to 3 GHZ).