Our build up is poorer on the right without Stones, which exacerbates Walker's lack of technique and the ball has to then recycle left, because Dias struggles to move it in to midfield and create the triangle.
It's also why Ederson is struggling at times in possession.
Laporte is able to switch a wonderful crossfield pass out to the right, but he doesn't offer anything else better than Dias can on the left from a defensive standpoint.
Dias is quicker and more alert and because he is naturally a right footed player playing on the left, teams have much more of a problem trying to decide which way the ball is coming out when Stones is also the right-sided defender.
It's just the better partnership and balance for the team.