Hypx_

Unless you think BEVs are the "final car," and there are no fundamental future advancements to ever be made, something like fuel cell cars are going to happen.

LED might a similar relationship to fuel cell cars since they work like the old kind and don't have huge disposal problems.

You can store hydrogen in underground salt caverns. We could store years' worth of energy demand.

This has never been an issue in the semiconductor industry until now. Demand was always increasing and margins have been high enough to allow them to self-fund. If semiconductor companies now need subsidies to expand then we are probably past the "exponential growth" era of semiconductors. Technological gains will be much slower and much more consistent with traditional industries rather one that what we're use to.

Even if we could magically upgrade every SFH to a multi-family building we'll have very unlivable cities with infrastructure falling well short of comfortably supporting the resulting population. So a realistic and worthwhile path to 100M would be a long and very expensive process.

So while this is an theoretical exercise but in reality it is very very hard to see happening under any short-term circumstances.