Kyrie is like a glass cannon. He is an elite scorer from all levels of the court. But Kyrie's frame is a little slight and it gets him injured at times. Also he is not really a leader. He is more of a free thinker and while that's not a bad thing in and of itself it has held him back from winning as much as he could have. Say what you want but it took LeBron's leadership for him to win his one title.
Jalen Brunson does not have Kyrie's level of talent but he has been coached hard since he was a boy. His father's coaching experience is invaluable. Jalen is a master of the fundamentals. He has elite footwork, he makes the team around him better. He not only performs in the big moments he seeks it out. He is a proven leader and while he isn't a blazing athlete his bulky build allows him to play through contact and get buckets almost at will.
People really underrate how much of an impact raw, brute strength makes on a basketball court because they’re too obsessed with verticality and leaping ability.
Luka, Jokic, LeBron, Giannis, etc. are some strong ass players but not all of them can jump out the building.
There’s nothing you can do when somebody backs you down and tells you to get in the weight room over and over again. If you send the team to cover, they dish out. The coach needs to then get that player out the game, rotate assignments shifting the lineup or eat the mismatch all night.
It’s an overall more reliable game and Brunson can keep going to it when the shot or handles aren’t working. So many NBA guards and forwards are skinny and light work.
Giannis mentions it here how having that post-up game is basically spammable in the NBA when all else shuts down: