Okay, I have a bit of an issue with track and field in the USA:
It's the lack of relevancy in the sport (due to it's tainted past) that is likely the reason that Allyson Felix is not on the same type of list as athletes like LeBron James, Serena Williams, Michael Phelps, Cam Newton, Tom Brady, Simone Biles, whoever the most recognizable face in MLB is now that Jeter has retired, among others in terms of household American sports names that casual fans recognize. That is too bad because Felix would be the reason for the sport to be relevant again in the United States, just like how Phelps made swimming relevant again in the US (with Katie Ledecky possibly continuing making the sport relevant). She has the accolades and everything else that you look for.
The casual sports fan in America sees LeBron James in a non-basketball commercial and thinks "basketball player" and likewise Cam Newton for football. If they see Allyson Felix in a commercial and she doesn't run track in that commercial, the casual sports fan may think she's an actress.
If she doesn't come back for 2020, it was a lost opportunity for USA Track and Field IMO, to make her a household name that casuals recognize ala LeBron and Cam. The biggest name in her sport that most casual sports fans probably recognize is Usain Bolt.