Ericsson and Nokia almost evenly share 96% of the total market in telecommunication equipment in the U.S. The U.S. declined to open its market to Huawei in a fear of data intrusion.
Huawei supplies smaller carriers and towers in the U.S., because Huawei offers lower prices.
I do not think it'll post any financial challenge to Huawei if they withdraw from the U.S. On the tech front, they may have to stop stealing.