Pritchard doesn't get a lot of love on this site would you all rather have Eric Bledsoe or Tomáš Satoranský as the third guard off the bench. Who else might shake loose?
Of the players who stand to benefit the most from the trade-deadline roster consolidation, Payton probably is foremost. When Brad was coaching him - as a rookie, mind you - he was given a regular rotation role to play, and his statistics reflected that, especially his long-range shooting %; mostly this season he's gotten spot minutes and a diminished role.
One of those old truisms in the NBA is that a player needs at least one skill that he really excels at.
You might argue (I would) that the modern rules skew toward guys who are more generalists, since in today's game it's easier to exploit a weak defender or double off a weak shooter (etc., etc.) than it was in bygone years. I would further argue that today's game favors team play, especially ball- and man-movement; and athletic players who can cover a lot of ground. It's just not as easy to "hide" a player on either end.
Payton is far from a one-trick pony, but his size and strength limit his court time. If he had more "point guard" skills he'd have been on the court more, possibly - but it's defense that has kept him on the bench for long stretches.
We'll see how he progresses his defense (and it just doesn't look likely that he'll ever play starter's minutes on a contender); but he's apparently got an outstanding work ethic. The greater part of defense is still effort, desire, and being in the right place.
And a skill that is highly prized in today's game: the range to shoot over the defense. I don't put too much stock in his shooting%s right now; this guy is an exceptional shooter with unusual range.