Why is a crop that could feed millions only cultivated in one place?

That's one way to interpret the response to the long history of botanical colonialism, including at Kew Gardens where Borrell works, which brought immense profits and power to the British Empire.

That's the unmentioned context behind:

> “There’s lots of examples in history of crops arriving in new places and being dominant,” explained Borrell. “So there’s absolutely no reason why it (enset) couldn’t be important somewhere else.”

One example is breadfruit, which the British brought from Polynesia to the Caribbean as a cheap food source for their slaves.

Since you didn't read, other factors are 'enset is currently “backbreaking” to harvest', ', 'Cultivation also involves an elaborate methodology', 'turning enset into food requires specialist knowledge', and 'The plant is also something of an acquired taste'.

The government of Ethiopia is not known for being able to effectively control its borders. I think the more likely explanation is that it's just not that amazing:

Roughly 60% of more than 400 southwestern farmers interviewed as part of a 2025 study by Kew and partners at Ethiopia’s Addis Ababa University said that the area of farmland they dedicated to enset had decreased in recent decades, with many also revealing a pronounced decline in household enset consumption.

Those farmers have no problem accessing enset, but they simply found better ways to feed themselves.