What is a limitation of 5g mmwave, despite its high speed?

Question: What is a limitation of 5g mmwave, despite its high speed?

Limitations of 5g mm wave are- 1.Vulnerability to atmosphere and other climatic parameters due to which it weakens the threat identification process. 2.high penetration loss and poor diffraction. 3.The operation of millimeter wave radar is affected due to interference from nearby electric poles, cellular towers, WiFi/cellular hotspots etc.