It's the treadmill of solving previously thought to be unsolvable problems. Each step is going to be more "See it's impossible", until it's not.

It's like saying that it's impossible to climb a mountain because, from a mile away, you can't see any handholds.

Obviously thermodynamic arguments that conclude with, "And so, we see that it's actually more efficient to house, feed, water, and slaughter real, live animals for meat," are ridiculously invalid. The same will eventually become true for the economic arguments in the article. It's 'just' a matter of asking how we get there from here, and putting in the R&D work necessary to make it happen.

And it was true, until cheap LI ion batteries became commercially available because they have the required power density to make it viable. From there it was just a matter of the economies of scale.