Why Exynos is not used by Samsung in the U.S. market ?
As background, due to a patent-related agreement between Qualcomm (holder of many patents) and Samsung, Samsung cannot sell it's Exynos chipset to other phone manufacturers:
Qualcomm Might Have Prevented Samsung From Selling Its Exynos Chipsets to Other Phone Manufacturers According to The Korea Economic Daily, Qualcomm abused the ‘standard essential patent’ license to prevent Samsung from selling its modems and integrated chipsets for around 25 years. According to the source, this is considered as an unfair practice and has been confirmed by the Fair Trade Commission.
To recap, the Fair Trade Commission had decided to fine Qualcomm $865 million over antitrust violations, which stated that the company violated the law of competition, but the chipset manufacturer intends to appeal the decision. The deal reportedly dates back to 1993, when an agreement was reached to allow Samsung to make its own modem chips using certain CDMA patents, but only for use in its own phones. Subsequently, either Samsung or the phone maker would've had to pay Qualcomm licensing fees if they wanted to use an Exynos SoC in a non-Samsung phone. Talks between the two to reach an alternative agreement reportedly broke down in 2013.
Since then, non-Samsung Exynos phones have been few and far between, with the Meizu Pro 5, being a rare example.
While Qualcomm's licensing terms may hold back Samsung's semiconductor business, the group has benefitted in other areas from Qualcomm's dominance. The past two generations of high-end Snapdragon processors have been manufactured by Samsung.
