The importance of small cells cannot be emphasized enough for emerging networks.
Emerging 5G networks need to meet very high performance goals of throughput (e.g., area throughput of 10 Mbps per square meter and connection density of one million devices per square kilometer area). Hence, densification is quite critical to emerging networks.
Small cells bring the base stations closer to the subscribers, significantly increasing SINR and hence throughput.
Furthermore, the same spectrum can be reused many times in a small geographical area, increasing the supportable capacity and throughput.