The reason the US is inefficient is because it has massive scale. Huge country, basically no-one lives there in population density terms (tbf, Australia is the same size and even less dense though...so not an outlier). The future will be about doing more with less, and the US is an example of doing less with more.
Simple. The room for innovation is still huge.
Saying vertical farming is overhyped is probably correct too. But that ignores the fact that this is essentially what Netherlands has been doing for two decades. Their ag research programmes have focused on minimising resource use for a long, long time. And it does work...it is working already, and has been for a long time. Call it overhyped or whatever but it is happening already (the level of hype is correlated to funding or whatever...this just works).