Because phones aren't a strategic asset with geopolitical importance. If China corners the market on solar then they would be able to undermine US energy produc

Because phones aren't a strategic asset with geopolitical importance. If China corners the market on solar then they would be able to undermine US energy production in any protracted war (shooting, trade or other), it would be the future equivalent of cutting off the oil/coal supply but with more lag time. Being unable to get new phones would merely be a personal inconvenience. China is highly dependent on foreign coal, so they also have a strategic interest in creating energy independence.