A player that is a much better play maker and shooter. Brown has no elite skills. He is good to very good at most things, but he just isn't elite at anything and he is worse almost across the board at everything than Tatum. He provides nothing you can't get from the better player. He doesn't elevate or compliment Tatum. I went through the first half of Udoka's season when Brown was in and out of the lineup in chunks (which made this a good experiment), and Tatum's stats were mostly the same, except for his shooting, which increased significantly when Brown wasn't out there and he was paired with a much worse player than Brown, but one that was more complimentary. And the Celtics during that stretch were 6-7 with Brown and 7-7 without him. Tatum just plays better when he doesn't share the floor with Brown, which is why Tatum's on/off differential is so much better than Brown's every single year despite them both starting on the same team and playing roughly the same minutes. The offense stagnates and isn't as dynamic when they both have to get theirs, but when it is just Tatum, it always runs through him and the team just plays better. There are obviously going to be games where Brown is the difference between winning and losing as he is a very good player, but he doesn't provide the value or impact that someone of his ability should.
Give me some examples of a similar level player you think would be better than Brown.
I'll play along. Examples are
M. Bridges Nets
Lauri markanen
Desmond Bane
So this is what I struggle with. I take Brown over all three.
Bane is not a better player than Brown and Markannen can't guard anyone. Both players would be defensive gaps in the playoffs. If you plugged either player into our lineup right now, either would be under 18ppg and could not provide the one-on-one defensive versatility that Brown does.
I could see how you could argue something about Bridges. But here's the struggle. The version of Bridges right now is not a better fit than Brown. The version of him when he played for the Suns might have been a great fit, but wasn't a better player than Brown. Bridges hasn't figured out how to play next to other high level scorers while being a high-level scorer himself and playing high level defense.
I would argue that Brown has more value than any of those players around the league right now. Plus, we don't have any kind of reliable playoff pedigree from those players.
If there was a player with similar talent that would fit in better, I could talk myself into it. But the players who get suggested on here consistently are not as talented and would not be as effective in big games.