And this local supply disaster noted, we kinda like it that way.
Lettuce likes some pretty specific conditions. If there's one area that's perfectly suited to growing lettuce with the minimum resources (fertiliser/water etc) then grow it there. Better than trying to grow it in the desert or somewhere much too cold.
If Australians go without lettuce for a month or so nobody is going to die. Eat rocket, spinach and cabbage instead.
There was big social media/news thing when KFC announced they were replacing lettuce with cabbage on their burgers.
A lot of unhappy campers there - tbh I think if they went further and made it a nice slaw with a sharp/tangy dressing then it'd be a massive improvement to their usual soggy, greasy chicken, and undercooked/limp chips (fries)
Worldwide there's an issue with regions being devoted to mainly a single crop intended to supply tens of millions across several cities, often overseas.
Good when it works, better have a backup alternative when that fails.
Carnarvon represent!