Booker has played very well in my opnion. You also have to consider several things one being he is by far the one Suns player the other team keys in on. Eric Bledsoe and Knight are back when Booker went on that run last year he was pretty much the PG/SG but he dominated the ball.
He's also 3rd in scoring among second year players behind Towns and Porzingas. I don't know what people want
The thing missing from Booker's game this year is consistency in his shooting, which will help bring consistent scoring. All of his stats I'm using from last year are after the All Star break when Bledsoe, Knight, and Warren were out and Watson was the coach. He's averaging 18.7 ppg this year compared to 19.2 last year on virtually the same amount of shots, 16.6 this year vs 17 last season, making 7 now vs 6.8 last year. So his shooting % has gone up slightly but is still just 42%. He's also shooting just 31% from 3 this season on 5 attempts a game. His scoring averages this season are a bit deceptive though, he's played in 23 games and has had 9 games where he's scored 13 points or less and also has had 4 games of 30 or more, which cancel each other out in a way and bring him back to his 18.7 ppg average. Out of the 23 games though he's only scored within 2 point +/- of his average 6 times this season. He's getting the same amount of shots but not converting as much as I'm sure anyone would like. With more help on offense with Bledsoe, Knight, and Warren returning you'd think his shooting % would increase but it really hasn't. Some nights his shot is on and some nights it's off, which happens, but instead of facilitating for others when it's not falling he's been forcing more bad shots trying to force his offense. He was a more willing playmaker last year despite having less quality players and scorers on the court with him. I think all of the hype has created some pressure for him and he feels like he needs to keep throwing up shots and make something happen rather than letting the game come to him some.
For someone who many predicted was nothing but a shooter coming into the league though he's shot rather poorly overall. 31% from 3 this season is bad, especially when he's shooting 5 a game. That should have gone up this season since there are more offensive players on the court with him and he's also not running the offense at PG like he was for a good stretch last year. I'm not sure if there are still issues with his toe injury he had ot start the season but I think that's the case because he seems a step slower than last year and he's only 20, players don't slow down naturally at that age. If it is his toe the Suns need to sit him for 4-5 days, no practice, no games. Let him get 100% and hope for the best when he returns. I appreciate his competitive drive and wanting to play through it but he's only hurting himself. Sitting him entirely for a few days would be much better than reducing his minutes, which might hurt his confidence. Ideally Knight plays great for the 2-3 games that Booker is out and the Suns can get a time to trade something of some value for him.