TheGeneral99 wrote:1) No one here is saying that Scottie is in league with MVP caliber players, the question is whether he has the potential to become a #1 option star.
2) You can be a #1 option without being a top 5 player...many people would argue that guys like Tatum, Mitchell, Haliburton, Butler, Brunson, Cunningham, Edwards, Booker etc. are solid #1 options, despite not being in league with Jokic, SGA, Luka and Giannis.
The OP specifically used the word "superstar,"  which does change the tone of the conversation some. But in general, a guy like Barnes is a terribly poor choice to use as a focal piece for an offense. He has other uses. He has other potential. For example, he has the potential to not be a historically-bad scoring threat this season and going forward, now that we're opening up the floor with more shooting, and perhaps less self-creation responsibility. A little more passing support could go a very long way to making him a more useful piece on offense. Getting him to stop taking ATB 3s would be another marvelous improvement for his game. Specific use case is so important for most players. Guys who aren't superstar offensive players, you can't just throw them in the pot and hope for the best, you have to position them for best success.
Look at Pascal. He's a very good player, but he NEEDS shots in certain places and lots of passing support for him to become an efficient player and be more useful at mid-volume scoring. With Scottie, it sounds like we need him around 10-12 FGA/g with a healthy dose of passing support and a high proportion of transition action. And we seem positioned to do that this year, which is good. 
It's very clear that he hasn't shown anything resembling what it takes to be a legitimate focal option on offense. He can't handle scoring volume and he isn't an ATG playmaker, doesn't have elite athleticism, doesn't have the jumper, doesn't have the elite on-ball game, doesn't have the consistent ability to get to the rim, etc, etc. He's just missing the pieces it takes to get there. It's all "doesn't have" with him, within the specific parameters of "can you land the focal responsibility for an offense on his shoulders." And that's about as expected based on what literally everyone was saying ahead of the draft. He can't shoot, he isn't a scorer, that's not where his strengths lie. Us shoehorning him into the role just to see while we tank is something else, and it's an experiment which now needs to end.
The future is hard to predict, remember that Shai in 2022, at 23 years old, had not even made an all-star team and averaged 24ppg on 45%fg and 30%3fg on a terrible team. 
At 22, he'd averaged 24/5/6 on 109 TS+ (62.3% TS) in his abbreviated season. A year later, he had another injury-interrupted season and backslid a bunch on his short game and struggled from 3. But he already showing elite ability to get to the rim and draw fouls, was showcasing his passing, etc. By the time he finished the 21-22 season (his age-23 season), it was pretty clear that he was going to be an extremely good player. He certainly broke out a year later, but he'd been flashing the pieces for a couple seasons already.  
That's quite a different scenario from Barnes. It'd be really difficult to go hunting and find someone missing so many of the different tools which go into elite offensive play who suddenly became a worthwhile #1. Like, even if you look at Demar's incremental improvement over aeons and aeons of basketball, he never turned into a guy who was a really quality choice as a focal player. He, like Siakam, ultimately led us in volume, but it was Lowry who was the real engine of our offense.