My biggest disappointment so far is that this is our 4th game of the season, and Jaylen Brown has only looked like the clear best player on the team in one of those four games. 
If Tatum was out there on the court with this mediocre group of guys around him he'd be averaging 30+ without question.  
I'm going to give him the benefit of the doubt while the team builds chemistry together, but if he finishes the season with these kinds of numbers it should well and truly put to rest any of the claims people have tried to make that Brown is on Tatum's level as a player.   He should be averaging close to 30 with Tatum out.
Nah, I disagree with all of this.
Brown has very clearly been the team's best player through the entire start of the season.  And people need to put the Tatum-vs-Brown thing to rest.  The dudes are on the same team.  Trying to measure the two is just pointless fan drama. 
Two players being on the same team has never been a reason to not compare.  People have always made arguments about Kobe vs Shaq, Lebron vs Luka, etc. Hell some people have even tried to argue Pau vs Kobe.  When you have two exceptional star players on a team there are always going to be comparisons.  
It's also not just Celtics fans creative this narrative.  It's been everybody around the league - opposing players, analysts, etc.  When Brown won Finals MVP how many people around the league were trying to claim this was proof that Brown was better than Tatum?
I bring this up because I think Tatum cops a LOT of unfair criticism from both fans and people around the league.  Tatum can put up 26 points, 12 rebounds and 7 assists in a series while also playing exceptional defence, and then at the end of the game people will throw dirt on him because he had a bad shooting night.   
We've seen how Tatum has responded when Brown was lost for the season back in the 2020/21 playoffs against Brooklyn.  Tatum averaged 30.6 PPG in that series, including dropping 50 to drag the Celtics to a win in game 3.  And that was in his 4th NBA season at age 22 when he had not yet developed his game to the level it's at today.  
Brown is an excellent player, but people need to realise that he benefits hugely from having Tatum out there on the court.  They all do - Pritchard, White, Hauser.  Tatum draws so much defensive attention that when he's on the court those guys get a tonne of open looks, and I think a lot of people fail to recognise just how many Tatum's mere presence on the court effects everything the team does.   
This is not an attempt to put dirt on Brown because as I already said, he's an excellent player and consistently plays at an all-star level.  All I'm pointing out there is that I think Tatum deserves more appreciation for all the things he does out there and all the ways he impacts games.