Only thing I can say is that heel faction leaders aren't held to the same in-ring or appearance standards as a solo top babyface is. As a heel it helps to not have exciting, varied movesets and to not be cut up because both of those things can lend themselves to getting heat.
Jey got the popularity and the crowd connection shyt
down, no question

But he's missing another needed pillar as a face.
As a top babyface, you either gotta have the exciting moveset, the top-tier selling, or you gotta be one of them faces that look the part of being able to run the fade with the world and keep going.
Either he gotta get with Sami and learn that psychology and underdog selling, he needs to up his in-ring offense to add more excitement than fittyleven superkicks and some pop-locking, or he gotta get himself into leaner fighting shape.
Can't have bland moves, be mid at selling for heat AND out there too gassed at the end of a match to stop a muscular orange man from MurderDeathKilling your partner when you 3 feet away and sucking wind to hit the yeets.
I like Jey's resurgence as a solo act, but as he is right now there is zero reason he should be going over what will be the next big crop of top heels: Drew, Gunther and Bron. I honestly don't even think he should be higher on the face order than Sami, all things being equal

Cuz learn a new hold, get himself a crisp new finish, or come out nicely in an extended feud with someone not blood related to him, I'll change my mind for sure.
But if you remove the catchprase... does Jey Uso do anything objectively better as a babyface than even a Wes Lee?