While I'm not clamoring for and zooming in on photos of elite runners' feet, I've considered brands and shoe models based on elites legitimizing them in my or others' eyes. I'd never have considered Hoka until I saw NAZ Elite runners in them, and then when a friend recommended a particular Hoka shoe to me I gave it a try. Same story with adidas and TME, I'd never even given adidas running shoes a second thought for almost 20 years until Hunter & co. were training in them. It's never straightforward, I'm not looking at Nike simply because Rupp and Hasay run in them, I have other reasons for discounting Nike. It might be, at least for me, "see someone I like running in that brand/those shoes, consider their success, see what people I actually know and trust think." This is all just a personal, anecdotal digression. Maybe it works this way for others, maybe not.
As to Rojas, consider the counter recent example of D'Amato. Not that different of an unconventional story, wasn't some superstar in college, took some time away from the sport for many years, reemerged as a top tier domestic marathoner without sponsorship. However, D'Amato stuck to what she likes, what works for her and she was rewarded. Rojas went with the highest bidder and found herself stuck in a situation she wanted to bail out of. D'Amato doesn't really have needs beyond getting her gear and maybe some travel taken care of. Rojas seems to be in a similar boat and perhaps could find herself a similar offer, it just doesn't look good to break contract before delivering on terms you'd agreed to. Nike may be happy to add another top-10 type American at a bargain, of course.