It is also relevant that in GM's few remaining non-NA markets are in:
China, where SAIC really is the force, thus supporting Buick through China domestic designs, often sold nowhere else, but with some exports to the US and elsewhere
Korea- through the Daewoo acquisition, supplied Asian RHD markets but quite them, and Gm Korea is not thriving at the moment.
Brazil- highly successful with almost all models designed in China or Korea, but built in Brazil. Mostof their success is by building the most popular taxi models in Brazil (the Chevrolet Spin, Onix and Cruze) and a highly successful pickup, the S10.
That boils down to GM having pretty much low end cheap models in China and Brazil (>50% of sales) and the North America steadily losing market share.
it takes no great analysis to explain why
@AudubonB found out GM seems not to have made consistent profits for decades.
They, like Ford, are retreating from the global markets bit by bit. Retreat has never been successful as a business strategy.
Just for reference Ford stays committed to the UK and GM stays committed to Brazil, while GM quit the UK and Ford just quit Brazil. GM is losing profitable share in Brazil because of Chery and Hyundai, among others while Ford in the UK is losing share to quite a few competitors, including Tesla.