The only way for a superstar to leave his team earlier than 8-9 years into his career is by giving up a ton of money (draft rights for years 1-4, followed by RFA and a 4-5 yr extension, depending on supermax eligibility). It’s only at that point that players really have agency in where they want to play, short of demanding a trade and hoping to make life uncomfortable enough for the team that they get it.

That’s part of why it was so remarkable when Bron, Wade, and Bosh all negotiated 3yr extensions after their rookie contacts. They gave up two full seasons worth of guaranteed money in order to reach free agency faster and team up.