Aldarc
Legend
I also think it's partially about how players see the cool things that their character can do. For some, that is why they created their character; they wanted to see how a build or concept plays. But once the novelty has worn off? Then what? Again, I think that some player can become bored and become ready to try a different character concept out. Not sure what to call this. Maybe "PC as Player's Toy."Your conjecture is an interesting one!
I can't easily internalise/intuit it, as I'm not really a "your build" player. But intellectually I can see it. Especially in conjunction with the idea of trivialising encounters - if the build is a type of power/optimisation thing, then seeing it come online and do its thing once or twice might be fun, but there may not be ongoing reward in that (and the GM may not be all that interested either).