The market is often either wrong or distorted by existing government policies. For some things, subsidies need to be involved to create a new industry where there isn't one. For others, subsidies are a waste of money leading to graft and excess. If I were the one with the credit card, I'd be betting big on hydroponics/vertical farms, medium to high density housing, and high speed rail.

Despite plenty of demand, high density housing still isn't getting built nearly as fast as it should. High building costs, zoning laws, and the ability to just suburban sprawl to infinity mostly prevents this.

Pretty much all vertical farming startups have gone bankrupt. There are endless benefits to vertical farms, but we don't do it because existing farms are cheap in comparison to the necessary investment to make this viable.

We don't build high speed rail because it's a multi-decade long project involving massive logistics, training programs, lots of land rights issues, and the fact that for short to medium distance trips people would probably still prefer to drive since once you get to your target destination, there's still no way to get around without a vehicle.