I've recently realised something about Pythagorean triads; a topic which very few people I know would be interested in hearing about... so I'm posting in here - a ghost town maths community. (But I'll also post on mastodon.). Anyway, the realisation is related to complex numbers.
If I have two complex numbers, I can multiply them like this: (x₁+y₁i)(x₂+y₂i), or like this r₁r₂cis(𝜃₁+𝜃₂). So then, if I represent a Pythagorean triad as a complex number, x+yi, with r as the hypotenuse, then multiplying two of these together is guaranteed to produce another triad. The rectangular method of multiplication guarantees integer real and imaginary components, and the polar method guarantees an integer hypotenuse. For example, (3+4i)(3+4i) = -7+24i. And 7²+24²=25².
So that's a bit interesting. But I have more. Since the polar angle in these triads is always an irrational multiple of 𝜋, repeatedly multiplying by the same triad will never return the angle to where it started. You'll just get new triads every time. But of course, if we are multiplying different triads together, its easy to come up with different ways of producing the same triad product. Following this line of thinking, we can view the Pythagorean triads as either 'prime' or 'composite'. Any triad can be written uniquely as a product of prime triads - just like with integers. (For this to fully work, we must allow 'flat' triads such as (1, 0, 1), (2, 0, 2), etc.)
How can we tell if a triad is prime? Well, I don't know - other than trying to brute-force the factorisation. If the hypotenuse is a prime number, then the triad is definitely prime. But if it isn't... I haven't thought much about that yet, but my current answer is to just check to see if a triad can be made with the factors of the hypotenuse.
Anyway, that's all I've got on that for now. No doubt there's some fully fleshed out details somewhere on a wikipedia page citing some well known facts from 2000 years ago or whatever. But discovering is more interesting that knowing. So I'm not going to check right now.
The cost of constructing and decommissioning power plants is important for sure; but it has nothing to do with energy density - which is what we were talking about before. It's true that building solar panels takes energy and resources, and the panels don't last indefinitely. So there is a lifecycle cost to using them. But the same is true for all forms of power generation.
A common way to compare these costs is to look at the 'payback time' of each form of power generation. The payback time is the amount of time it would take for the power plant to produce enough energy to pay back the lifecycle costs required to build, operate, and decommission that type of plant. It's basically how long it takes for the construction to have been 'worth it'.
In terms of payback time, wind power is by far the best; typically taking less than 1 year to pay itself off. Solar is pretty good too, but is highly dependent on where it is used. And nuclear... is not good on this measure. It takes decades for a nuclear power plant to pay itself off, because the plants are very expensive to build and decommission.
Obviously there are other things to consider in terms of the strengths and weaknesses of different forms of power generation. But you've been talking about the cost of materials and construction as though it is a weakness of renewables, and it really really isn't. That's in fact one of their strengths, and a major weakness of nuclear. Its strange that you say nuclear is 'insanity powerful for its cost', because its cost is the greatest weakness of nuclear power. Its much cleaner than coal, but much more expensive, even though it uses so little fuel. And it is not cleaner than solar or wind, but it is still more expensive.
Your point about land usage is a stronger point in favour of nuclear power... except that depending on what country you are talking about, that could easily swing the other way. Solar and wind do take up more space than nuclear, that's for sure. But nuclear requires certain geological conditions for the safe operation of the plant, and the storage of waste. So depending on where you live, finding unused land suitable for renewables can be much easier than finding a suitable location for a nuclear power plant and waste containment facility.