I have a strong opinion on this. It would vary by player but generally speaking a younger player needs the playing time to figure out what his niche in the league is. Some enter the league already pretty good at this……Grant, Leon Powe, Pritchard, Olynyk. These are typically the more physically mature “low upside” guys. The rest, like you say, need to figure out who they are. Perfect example is Javonte Green, even Gerald Green back in the day who was able to carve out a pretty long career once he recognized his strengths/weaknesses. This is Romeo, Aaron, TL, etc. The more athletic and higher upside a young player has the more playing time he needs to learn how to utilize his athletic skills……the low upside guys who lack the athletic skills don’t have to worry about that as much and are even susceptible to being overexposed when asked to play behind their role.
On the flip side, once you’ve established what you are like a George Hill, PJ Tucker, etc……you are basically worthless to a rebuilding team as you don’t need minutes to figure it out since you already have. These guys need the right situation more than they do minutes. I read everywhere how these guys are “toast” or “declining” but it’s nothing but a head fake as it’s often said when a role player is in a bad situation on a losing team.