Yeah, I was concerned about the creativity thing early one, but both of my kids build random stuff from a sea of parts. Occasionally my older kid would decide to build a set again and be frustrated when they couldn't find the part they needed.

As a family, we have a couple of the ninjago city sets, those are largely intact, but the kids play with them.

The minifigures can be a little bit of a problem, they seem to trigger an instinct to collect unique items. My kid will ask for a set so they can get one (or more) of the minifigures in it.