Popovich's decision to start Jeremy Sochan as the de facto point guard came as a big surprise to many Spurs fans. After all, it had been assumed that Tre Jones would start the year at point guard. While starting Sochan over Jones will lead to some growing pains since Sochan isn't the playmaker that Jones is, there are some benefits.
For starters, it would allow him to play big minutes as opposed to coming off the bench and being limited in that regard. He will also get to play with the ball in his hands much more than he otherwise would have playing with the second unit. That might not result in him playing point guard full-time but that could help him expand his game.
He'll also be able to spend more time playing alongside Wembanyama. That is likely with the eventual goal of having Wembanyama slide over to center and having Sochan play power forward. Factor in the experience he'll have a ball handler and the Spurs could use him as a point forward or secondary ball handler once they find a long-term option at point guard.