I did not read any of your linked articles, but the answer is yes, fossil fuels most certainly would have dominated the 20th century because they are:
- Cheap
- Stable, you don’t have to depend on the sun shining
- Nobody really cared about climate change back then, they were estimating a few centuries and humans… aren’t that forward thinking
Edit: I was beaten by another commentator lol
I fully agree. In cities and places with a grid, fossil fuels will absolutely dominate, while rural grids/independent homeowners could use solar. However, I do think the cost of acquiring such panels could be prohibitively expensive for some rural homeowners.