Steve Kerr, Brad Stevens, and Greg Popovich are much superior.
There are bad coaches like Fred Hoiberg or Mark Jackson who Stotts is much superior to.
I don't think Stotts is worse than Mike DAntoni. That team was in a position to win the title if CP3 wasn't hurt or it's players could hit easy shots. With the right roster Stotts could coach a title winning team.
To the original poster, the problem is Nurkic is in a league where the advantage of big over small is much less than small over big. Kuzma on the Lakers destroyed Nurk forcing Stotts to remove him. The Nurkic contract could harm the team if we won't be able to play him in playoff series.
Wrapping up the coach angle, I do think it's possible to have a better coach than Stotts. Problem is none of those are available. A coach like Stevens NBA successs was unknown when hired. Hiring him was a gamble that could as easily turned into a Fred Hoiberg. If we fire Stotts it's far more likely we end up with a worse coach than a superior one.
Right now this team roster is 95% of the problem so fixing a coach or other changes won't make us contenders.
Most likely no action will make us a contender.
The best chance to contend is if somehow Neil makes a great trade or we hope one of our players improves to a star. Either is not impossible, but certainly not likely. Replacing Stotts is a bad gamble that hurts those chances more than it helps.