I go back and forth on this one. On one hand, it does not really add anything and for a long time I did not really use it. There isn't much point without an appearance system (or a more crucial one). ...
I only use a couple of clutter items in my builds, just enough to place on shelves without using MOO. I watch a few well-known builders' speed builds and love how the homes look, but I would not want my Sims to live in such cluttered spaces.
I do wish there was more variety of clutter to fit Sims' personalities.