It's a tricky situation at SF. This team needs scoring, defense, and three-point shooting. Warren can score, and does so efficiently. Jackson can defend, but he is really undisciplined and makes too many mistakes. Neither can shoot, but Warren at least knows that he can't shoot. Hell, Bridges checks more boxes than either one of the two we are discussing, but I think that for now, they really need Warren's scoring. Ayton is a rookie, Ariza is not a great scorer, Knight, even at his best, was streaky and unreliable. Having another scorer will help Booker and others. This isn't even necessarily about Warren, it's just about the lack of scorers the Suns have.
Hell, even looking at the rest of the roster, I don't see any great scorers in the future. I really like Bridges, but he will be another Ariza. Bender, even if he develops, isn't gonna be a volume scorer. Best case scenario for Bender is a 7'1 Ariza, or perhaps Ryan Anderson who can play defense. Best case scenario for Chriss is a little bit better offensively, but I think that's not likely to happen. Jackson could turn into a good scorer eventually if he can calm down and play within the system, but I don't think he will be a 20ppg-type scorer. Okobo may surprise us, but I think he is a couple of years away from contributing. Reed is another 3 and D guy who isn't gonna be a crazy scorer.
They really need Ayton to become a scorer, and then they need another scorer, or at least a bunch of really good shooters surrounding him and Booker.