I probably see fewer players as superstars than most do. Superstars are the most productive players in the league, the leaders on their team, players who generally keep their team in every game, and produce at a high level consistently.
Current Superstars -
Giannis Antetokounmpo
Stephen Curry
Luka Dončić (I waver on him because he's not a good defender)
Kevin Durant
Joel Embiid
Chris Paul (he picks and chooses his spot for asserting himself sometimes)
Lebron James (not much of a defender anymore)
Nikola Jokić (has some defensive issues, but his offense is stratospheric)
Used to be, but have slipped -
Anthony Davis (availability is the best ability)
James Harden
Kawhi Leonard (availability is the best ability)
A few questions you have to ask are -
Is he efficient? (Does he shoot a high percentage? Does he turn the ball over too much? Does he get the team more possessions through defense and rebounding?)
Does he play both ends of the floor? (A big strike against Trae Young. Booker has improved a great deal defensively since he was a teenager)
Is he dependable? (Does he play most nights, and when he does is he consistent)?
With the Suns I would say... Paul? - yes. Booker? - not quite there. Ayton & Bridges? - they both look to be longshots unless they develop more consistency offensively and become more assertive on that end of the court.
Superstars in Suns history - Connie Hawkins, Paul Westphal, Kevin Johnson, Charles Barkley, Steve Nash, Chris Paul