I don't anyone doubts the speed potential of mmwave. It is just that this tech doesn't scale well in most situations so you get those speeds only in very limited scenarios.
Qualcomm is (still) a vociferous proponent of the potential of millimeter-wave (mmWave) 5G in commercial applications. Now, the company claims to have leapt a key hurdle in its race to become a major supplier of standalone mmWave in China. It involves the achievement of multi-gigabit per second (Gb/s) peak download and upload speeds using the Snapdragon X65 5G Modem-RF System.