"Why use a solar panel that only absorbs 10% of the solar rays when you can at least absorb 50% - 60%? Or even 80%."
Cost effectiveness. This is something you'd have to consider whether you were a die-hard capitalist or a die-hard communist. What it takes in real world economics to put cells of that efficiency anywhere, even on the Earth, is very high. The best of solar cells doesn't even get 50% on Earth currently, and Solar cells see their effectiveness multiply when placed in space due to the lack of atmosphere.
As far as your cost analysis goes, though, you've missed a key factor. Solar techonology hasn't decreased (significantly) in price in a long time now despite cheaper production costs and advancing technology. In reality, the rise in demand has outstripped everything else and caused prices to remain stable (or raise) because the necessary silicates cannot be produced and chemically alterated fast enough. The more we push the tech, the more it costs, and the more energy it puts out the more demand prevents costs from dropping by ensuring that supply is smaller than demand.
As it stands, solar tech isn't getting cheaper even though production (and, obv. by extension, demand) is rising, and new advances in the field don't help that. The best way to circumvent the supply and demand issue is to move to a system where supply can't really be constrained (the moon), yet the costs of doing so are enormous.
If you try to replace that tech with terrestrial sources of power production you MUST eliminate land that could potentially be used for agriculture (deserts are too far away from most large centers of civilization to be usable) and that increases food costs which doesn't help civilization at all since it doesn't mean a damn thin if you can power everyone when you can't feed everyone. Rooftop solar power isn't enough to cover areas with high population density. Even with the advances you've mentioned, which aren't anywhere near practical yet, the panels would only be enough to power individual homes in temperate condititions. Apartments would still require centralized power, population dense reas would too. Only rich people who already sit on a lot of land with a big house in sunny areas would really be covered.
You do not have the right to never be offended.
