Watching the entire game last night, the problem is really obvious.
Giannis' teammates lack of trust in him.
The guy is a world class talent, but he is not confident at all in his jumper. Or, let me rephrase -- his TEAMMATES are not confident at all in his jumper. Giannis would pass it in, and he'd never see it again, because his teammates wanted to shoot. Example. In the 4th, I forget what minute, but it was a key part of the game, the defender backed off Giannis, and he hit a 3 from straight on. Once that happened, the defense couldn't sag off him. But instead of going back to Giannis, who with his passing, and now some respect from the defense on the perimeter, the Bucks players just stayed away from Giannis and tried to do it themselves. HUGE, HUGE bonehead move.
If Coach Bud is smart, there will be a concerted effort to establish Giannis from the start, both inside an out. But Giannis will have to show patience, and his teammates will have to trust him. If they play the way they did last night on Saturday night, the Raptors are going to the Finals.