You have to have the "Total Package"* to succeed inn the WWE and most American promotions you have to show Size Strength Agility but most important since the Attitude Era you have to be able to cut a Promo. Look at Braun Strowman he looks the part but cant cut a promo same with Karrion Kross and up until recent Drew McIntyre., they did a good hiding some guys like Kane but the Fans want more.
Some guys arent WWE material, I dont think Kenny Omega is anything special on the Mic and because of that he wouldnt be as big a star in WWE as NJPW. Cody sucked left and developed his Promo skills and now is a Rockstar.
Guys like Ricochet, Ali, Andrade and , Wardlow and Hobbs can all learn from Cody on how to rebrand yourself out of mid card status.
*pun intended I was a huge Luger and 4 horseman mark if you cant tell my love for stables,