The entire trade IT narrative is built on comments that respectable Boston reporters said during a podcast. The conversation was about getting the assets to make the Butler trade. Overall, I think the narrative of trading IT should only be in the presence of getting a two-way star like Butler.
The trade IT movement makes fair points about the imbalance in his game and his upcoming contract. One thing I'd like to add is if you take away the quality of role players that support IT, the team will fall back to late lottery team.
It was no coincidence he has succeeded in Boston. But back in Sacramento, he only contributed in putting up individual numbers. After signing with the Suns, there haven't been improvements in his game beyond taking on larger offensive responsibility.
This only goes to show he isn't the reason why the team is winning. In actuality, the strong defense has given Isaiah a platform to say he is responsible for the wins. You let him sign big for another team, he will be on a perennial late-lottery team and that team will regret overpaying.
This is why IT doesn't deserve a max deal. Until Isaiah realizes leaving the Celtics to chase money will guarantee life in basketball purgatory for the remainder of his prime, I think trading him or letting him go are the best options. Things will turn 180 if he realizes he needs to take less money because the winning has been because of the team's success.