There is a lot of stuff that people said about this solar that got overtaken by reality. And some of those people were proponents even.
People have underestimated economics, learning effects, and the effects of increased scale. Mostly the exponentials were actually pretty clear to some investors as early as 15 years ago. And the success those investors have had, has driven more investment.
The thing with exponential trends is that doubling a little bit results in a little bit more. It doesn't add up to something people notice until suddenly it jumps from fractions of a percent, to full percents, to double digit percentages in the space of a few years. That threshold got crossed a few years ago and people started to notice. And that's now leading to further price drops and more adoption. Of course, it's not a real exponential but an s-curve. But until the curve flattens, you won't be able to tell the difference.
Back of the envelope calculations can be misleading because they tend over simplify and make silly assumptions. Like assuming we are going to move 100% of energy to solar all at once. In reality, what we're doing is a decades long transition where most of the decision making is cost driven and the energy supply is coming from mixed sources.
We don't have just solar. We have existing nuclear. Existing deployments of coal and gas, which like them or not are not going to disappear overnight. And a lot of onshore and offshore wind. And a rapidly growing amount of batteries and cables which give us the ability to time shift supply and demand and move energy around over large distances.
The world's electricity consumption is about 30 PWh per year and will probably grow to 35 or 40 soonish. Most of that growth (>90%) will be powered by renewables. It's outgrowing everything else by a large margin. And because they are cheaper, there is also pressure to replace existing generation with renewables. That basically happens based on cost and age of plants.
This is another effect that people keep underestimating. The reason coal generation is rapidly disappearing from many markets (and is completely gone in some of them) is that replacing them with cheap renewables is cheaper than continuing to operate them.
That same effect is going to affect gas generation. Anyone building gas plants with the expectation that they'll have a 60 year life span is dreaming at this point. These investments should be considered as under water at this point. By the 2050s, most currently new gas plants will have probably have been mothballed (maybe kept around as rarely used peaker plants) or demolished. They are simply too expensive to operate relative to renewables. Some places keep gas prices low via subsidies (the US for example). But even there gas plants are going to face a reality check. And for a lot of countries, gas imports are a drag on their economy. Germany is a good example.
Worth observing what investors do here. They tend to have long term outlooks.