When does expansion become a problem?

I keep noticing this with people who move fast in business.

At first, expansion is a good thing.
More projects, more growth, more opportunities.

But after a while, something changes.

Not everything gets better.
Some things start breaking.

And instead of fixing those things, people just expand again.

From the outside it still looks like ambition.

But sometimes it’s just avoiding dealing with what’s not working.

I’m curious how others see this.

When do you think expansion stops being smart — and starts becoming a problem?