United Airlines is not a massive operator from the US to South America. Schedule analysis using Cirium information shows it is only the fifth-largest carrier by seats for sale in the first half of 2024 (January-June), smaller than American, LATAM, avianca, and Delta. It has fallen from third place in 2019 as others have grown much faster. United's geographic dominance is, of course, to Asia, Australasia, Europe, and the Middle East.