@godfather ,
I don't think anyone really feels Porzingis is better than Kyrie. If anyone really feels so, he is just plain wrong. Now, if I were in Knicks position, I won't trade Porzingis for Kyrie either. But not because I think Porzingis is a better player than Kyrie currently.
Rather, because of the fact that I can have Porzingis for the next 7 seasons at the very least compared to 2 from Kyrie. Also, potential wise, I genuinely do feel Porzingis is a generational talent. Does he need to work on certain aspects of his game like rebounding, putting on some muscles and improving his post-up game? Yes. But he is still 21 with so much scope for improvement.
As of now KAT, Embiid, Jokic are all better big-men than Porzingis but he has the potential and skill-set to be as good as those folks. I see his case similar to how I see Kyrie's case with respect to Curry, Westbrook, Harden etc. Is Kyrie as good as those guys yet? No. Can he be? Yes.
So, will Porzingis ever be as good as KAT, Embiid and Jokic or will Kyrie ever be as good as Curry, Westbrook and Harden? Who knows! But, both certainly do have the talent imo!