I think this is a weird framing of the issue. Sure, lots of businesses go under, and maybe being larger would have saved them, but maybe not. Plenty of VC-funded businesses go under precisely because they tried to be too large, when they could have perfectly comfortably served a few satisfied initial clients for enough money to pay all their bills.
I think the idea that companies go under because they aren't ambitious enough says more about modern attitudes towards growth than it does about the reality of business.
When I say growth I mean net profits. Those imploding VC companies were never profitable.
A larger profitable company has more chance of survival by shrinking into a smaller profitable company. It's a buffer. But an already small profitable company doesn't have that option, there's more risk.
I think the idea that companies go under because they aren't ambitious enough says more about modern attitudes towards growth than it does about the reality of business.