Barry has said some ridiculous things.
Barry is also one of the greatest players in NBA history. Most of you were not born when he played. The guy was a great player. Look him up. He took a team of nobodies (the '75 Warriors, I think), and won the NBA championship vs the heavily favored Bullets, in a 4 game sweep. This accomplishment makes what he has to say about what it takes to win a championship, RELEVANT.
There is also some legitimacy to his comments. Jaylen particularly, Jayson less so. Their career assist averages relative to their usage is quite low. Zach Lowe laments this often in his podcasts. There is some truth in what Barry is saying. They do commit too many turnovers, especially in the 4th quarter, when they press too much to take over the game. It is probably a major reason Brad made the Porzingis trade; to give them a viable option in crunch time.