At some point though, what more can you do with characters? After a while the viewer knows everything about them and the setting they exist in. There's nothing

At some point though, what more can you do with characters? After a while the viewer knows everything about them and the setting they exist in. There's nothing more to flesh out. I grew up watching the Simpsons every day. I stopped watching because I didn't like the new episodes, but also because there was nothing any of the characters could credibly do that would surprise me, or that I hadn't already seen them do.