Possibly, but this runs into the expression part -- can I express a simple character as well as a complex one? Does the complexity make any real difference to play, or just to my performance? If just my performance, am I actually roleplaying better, or am I better at performance?
This, to me, is another key distinguishing feature -- the difference between performance and roleplaying. These are too often intermingled such that a good performance is often mistaken for good roleplaying. I've done this myself when I've put on a fun silly voice and exaggerated a trait of mine to express a character that was highly entertaining but really not different from me at all.
Well, I did once start
a thread to explore the premise that RPGing is not a performative endeavour (I used the term "literarary" to convey the same idea) but found myself on the minority side of that proposition!
I think that complexity of character should make a difference to play - if it's just there in your backstory notes but never emerges in play, then what can I say: the backstory was a lie!, or at best a set of gears spinning idly.
In RPGing, given that most of us are not professionals, I would set the threshold for complexity pretty low. But at least a couple of potentially conflicting motivations can help: in the video Colville notes that Luke Skywalker both
wants to do the right thing (so he won't break his promise and leave the farm) and
wants to go off and be a hero (and hence wants to help the Princess). Colville notices how this conflict is resolved - the Stormtroopers kill Luke's aunt and uncle - but doesn't discussion how this could be done in a game (indeed, he seems to assume it would be a unilateral GM move to force the PC onto the quest). In a less railroad-y game, though, this looks like a failure narration that flows in some fashion out of the fact that Luke had to track down the droids and then wanted to learn where they came from.
And we can see how Luke gets a
new second motivation once he sets off on his quest - he
wants to learn how to use the force. And this again conflicts with his other motivation, because pride and the longing for glory lead to the dark side.
As may come through from the above, I quite liked the Colville video - especially its critical treatment of characterisation/"the voice" - but found it a bit disappointing in that it didn't engage with the techniques and authority-allocations that allows complex ("three dimensional") characters to emerge and matter in play.