Only one telco on Earth has publicly committed to a large, millimeter wave 5G build designed for true gigabit service: Verizon. The Europeans are all using 5G Low, 70%-90% slower.
STL Partners, a British consulting outfit I respect, commissioned me to ask why. That report is now out. If you're a client, download it here. If not, and corporate priced research is interesting to you, ask me to introduce you to one of the principals.