Wireless traffic growth is falling across the developed world, but the 2018 figure from Swisscom is lower than anything else I've seen. The Swiss figure may be an anomaly, but Cisco's VNI, a respected source, sees Western Europe growth in 2018 as 44% and North America 42%. In 2022, the Cisco projection is Western Europe 35% and North America 31%.
Update 5/12 Iliad/Free in France announced 28% in 2018 (end) In the developed world, the era of exponential growth is long gone. 100% annual growth is now just a memory, that ended when most of the population acquired smartphones. In India and Africa, only a minority have smartphones today, so growth is higher.
Verizon and AT&T both estimate wireless productivity growth of ~40% per year. Traffic growth and declining cost per bit roughly match. The result: Cost per customer is roughly flat. If prices are roughly flat, which is common, profit will remain roughly constant. In 2017 & 2018, profit at most major telcos has risen slightly. That confirms the Verizon and AT&T productivity estimates.