With the advent of 4G the use of mobile broadband has increased significantly and in some areas the speed of the connection is good enough to support a number of users. For professional use high gain antennas can be used to improve the signal and often multiple 4G connections are aggregated to provide more capacity and improve reliability, especially when the connections are aggregated from different mobile operators.
Data costs can be significant so 3G/4G is not ideal for high volume, but most importantly 3G/4G cannot be relied on for critical services. Although there are ways to improve the service there is always the risk that the connectivity will become overloaded from other users in the area, this is particularly significant for events where the service may run fine until attendees arrive and then the performance falls off.
In towns and cities the service is quick to deploy and great for general ono-critical use, in more rural areas capacity can be an issue even if there is a relatively good signal strength.