There's more to "the basement" than keeping it small, I think. There's also the aspect of dreaming; of shooting for something really, really big & exciting. There are a few businesses that scale without growing the size of the team much, but it's still extremely hard. For the most part, either you stay small and lose the ambition-excitement, or you get big.

Personally, I'm really not convinced that one is better than the other.

The dreaming is important. I'm now in a startup past the phase of "changing the world" and into "finding any small market to keep us afloat". The excitement is definitely gone. I find myself buying a coffee, taking a walk, pretty much anything to avoid actually getting to work in the morning. Because once there I'm doing little that anybody will care about. Except our investors of course.

if you're that unhappy, why not leave?

Stock. Inertia. Loyalty to co-workers. The usual.

I think optimally, if you like the basement and your business is growing out of it, you sell it to someone else who likes big, and find yourself a fresh basement.

The thing is that you don't know how much you will miss the basement until you leave it