Being the most popular sport league is not the same as being the most popular sport. Out of ten league positions, basket has #1 and #10. Soccer has #2, #3, #4, #6, #7 and #9.
Also, you see people wearing NY Yankees hats globally. Some of them don't even seem to know anything about baseball and just think it is some sort of NY merch. But still there are absolutely American sports teams that have recognizable brands more globally.