I gotta disagree with you there breh (unless you're referring just to the promo side of things, in which there I mostly agree with you) and that's one of my biggest criticisms of AEW and Tony Khan right now. He doesn't have a creative bone in his body, he has come up with 0 interesting original characters.
Mean Mark Callous came to WWF and became the Undertaker
Glenn Jacobs was Unabomb in Smoky Mountain, came to WWF and became Isaac Yankem (flop) Fake Diesel (flop) and then Kane
"The Natural" Dustin Rhodes came to WWF and became Goldust
Cactus Jack became Mankind
Sean Morley was "Steele" in Mexico under a mask and became Val Venis
I can't say for sure just how much individual input the wrestlers themselves had in coming up with those gimmicks, but the bottom line is they made a character/gimmick that elevated each of those guys to something new.
in AEW every wrestler comes in exactly as they were in the indies, same name same gear etc. Sometimes it takes a booker going "The Cactus Jack character is okay but we have this in mind" or "We want you to be known for something other than being Dusty Rhodes's son" and creating a character for a talent to take them to the next level.