These definitions have been conveniently inconsistent over the years. When people say superstar in an NBA context, which they casually say all the time, they're often talking about performance. Duncan and Jokic are referred to as superstars. Even Donovan Mitchell and Brunson get that superstar label.
Then people want to redefine and combine it with upper echelon off the court popularity (or come up with new terms like megastar) often times to elevate their favorite or preferred players over those that routinely bust their ass (pause)... so Allen Iverson or Carmelo Anthony are superstars but Duncan and Dirk were not.
It's honestly whatever makes ppl sleep better, as Hali don't need to be a "superstar" anymore than Duncan; your big market team and superstar player still gotta deal with him bustin they ass and taking their Finals spot.