Early 2019 GSMA Intelligence data show 737 million IoT connections at the Chinese carriers, more than half the world total. The U.S. has 109 million. Italy, Japan, and Russia have just over 20 million. The data is from GSMA, the primary source for world wireless data.
China Mobile had 551 million at the beginning of the year and expects to add 300 million in 2019. None is 5G, of course, showing 4G can accept many more connections. Massive video surveillance is the only application in sight that might require 5G capacity. Of course, the low cost per bit of 5G is always an advantage.