I guess the 400h is the low hanging fruit, she is the best in the world right now. However, if the trend continues she could be competing for medals in the flat 400 in the next 2 years and who would choose to run the hurdles over a flat race? The way it works is, athletes gravitate to the easiest event they can have success at.
Yeah but having a world record would be pretty nice. And that’s impossible in the open 400m.