[PKop]

The tropes page mentions there's a bit of distinction between writer's figuring out the character; flanderization is addressing the point after the character is basically fleshed out, then accentuating whatever they are, often past the point of caricature as time goes on. So more of a long term process. I agree it doesn't have to be bad thing, I'd go so far as to say it is inevitable to large degree. It is writers jobs simply to manage this natural/inevitable dynamic, be careful with it, and eventually end the show before it loses it's appeal. Sort of a lifecycle of "success" of writing interesting characters especially in sitcoms where personality/humor dominates story, and there will be diminishing returns as character evolves to self parody.