Every RTLS technology has its advantages and disadvantages.
Bluetooth Low Energy (BLE) is a highly popular standardized wireless transmission protocol. Its biggest advantage is its ubiquity with many products available in the market with continuously lower prices. However it was not purpose built for RTLS and suffers from tag-density, location accuracy and battery life limitations.
Wifi RTLS is the oldest RTLS technology and like BLE enjoys extremely high popularity in the marketplace. Tags in this technology suffer from short battery life and the system is limited in tag density and location accuracy.
UWB is the least ubiquitous solution in the market but provides the highest accuracy, longest battery life, and highest tag density among these technologies.