Let me know when truly calorie-dense foods like potatoes, corn, and wheat are finally profitable to grow indoors. All I see thus far is lots of LED-fed salad.
Vertical farming (defined as the inefficient use of indoor farming, versus greenhouses which are an efficient use of indoor farming) is not a good replacement for most sorts of food production. It's a potentially competitive way of producing the most delicate and high-value items as close to the customer as possible.
It could make it possible to sell some foods, like apricots, in the city which are otherwise impossible to ship because they have to be picked soft.
Often though, there is roof space available where high-value crops could currently be grown efficiently in greenhouses and it's not being looked at because of the VC focus on tech and growth.
It's not like 1 is a goal: we can't eat fossil fuels (or solar energy), and we know that eating either plants or animals is never going to yield all the energy they absorbed during their lives.
And even pre-industrial agriculture had specific elements which had a yield of less than 1 by this metric, in order to make specific things that humans wanted to eat. Since most humans don't like a diet of grass and oats, the huge excess calorie yield from those crops could subsidize low-yield farming of vegetables, meat and other delicacies.