Around 2008 Ericsson was the largest telecommunication equipment provider in East Africa. They used to supply around 70% of SCOM GSM network equipment.
Then Huawei happened, their stuff way way cheaper than Ericsson or Nokia-Siemen.
GSM is a standard and the equipment manufactured should be back and forward compatible and this was the basis by which SCOM was able to switch very fast to Huawei and ZTE.
Most of the network upgrade to 3G and 4G is by Huawei due to cost. Initially the stuff from Huawei used to fail but over time their quality has improved. Huawei is now the largest vendor of telecom equipment in the world and is the leader in 5G.
Spying concerns by the US are very valid. The CIA spied on foes and allies using sabotaged encryption equipment sold to foreign countries.
LinkChina was recently accused of spying on African governments at the Chinese built AU headquarters which uses computer network equipment supplied by Huawei.
LinkSCOM and Huawei are too intertwined from infrastructure (3G and 4G network), modems, phones and even equipment maintenance.