The question is what is physically sustainable, usually traded off against what is profitable, and profitability wins every time.
If you haven't noticed yet, you are bound to notice soon, the ultimate effect of all things being dependent on making profit, which is energy exclusively extracted from the planet, has to be destruction, complete destruction of everything, including with all the things we are already seeing leading up to it, all the global warming, all the wars, all the genocide.
The requirement for profit also affects even modeling work done to try to predict when things like the Kessler event (And global warming, for example) happen, it literally warps reality.
For example, look at the wording in this expert discussion of Kessler event probabilities - https://aerospaceamerica.aiaa.org/features/understanding-the-misunderstood-kessler-syndrome/
There we see these words; "Rather than relying on Kessler’s original mathematics and analysis, the experts are applying newer mathematics and models to simulate how debris and spacecraft interact in orbit".
If the orginal mathematics of Kessler Events does not identify the Kessler event, then what does? And what is it, exactly that these new mathematics are identifying, if it isn't Kessler Events?
Why even bother trying to update the mathematics, if by definition, it has not yet been shown to fail? Who is funding that extra research to modify the definition? For sure it will be Space X, who don't like what the original Kessler event definition was predicting, because it makes investors hesitate, before diving in. This has to impact profits.
Every investment in research since the latter has become for profit, has to show returns, in terms of profit. That is the only criteria of modern "Successful" research. This is what it has come to, in a world of ever decreasing availability of energy to extract, to feed profits.
Profit, is energy derived from destruction. It has to end in destruction, it can never end in a good result, (ie creation/ reduction of entropy), it has to always end in destruction. This is the simple hard truth, if it's done for profit then it will end in destruction, which is obviously unsustainable, it ends when all life is destroyed.
We won't stop the zits by just sticking the sweets to our face, we actually have to stop taking the sweets, to stop the sweets destroying our face.
We have to stop profit, and only the energy of the sun is incompatible with profit, physically impossible, so its moving to the energy of the sun we should be aspiring to do, to solve all the other problems.
Would we still want or need military grade short term low bit-rate communications if we were solar powered? Probably not, we'd be perfectly fine with also the up front costs of mega broadband, fully cabled fibre to all places, becauase we would be issuing money for free, reflecting product created by energy given for free by the sun, to everyone inclined to put that infrastucture in, for the benefit of humanity, fully funded and enabled to do that.
