I don't think you understand how this works. People voluntarily do this. No one is forced to. Public power providers exist and work. Balcony solar is added and helps save some cost because you don't buy those 800W from the public utility provider.
In my childhood everyone (like your parents, your neighbors, all the ordinary people) were growing potatoes. Highly decentralized and fully voluntary sustainable food production, sounds like a dream. This happened of course because the state-run economy created food shortages.
Economic sense is largely defined by the economic policy set by the government. No one puts balcony solar in France, somehow their economic sense is different.
So it isn't that France economic policies have made installing balcony solar unattractive, it's the permitting policies which are blocking people from installing more.
You have it inverted, pun intended.
Germany has very high electricity prices, even higher than the US (see https://worldpopulationreview.com/country-rankings/cost-of-e...), and this is due to policy failures in Germany. That's what makes these balcony systems so appealing.
I'm not sure that the outcome of having a lot of decentralized solar generation is a bad outcome.
It's a both-things can be true, even though France has also been getting more issues with electricity generation from its nuclear fleet caused by droughts, and high temperatures in their cooling water supply.
While I agree that you can't just arbitrarily raise safety-based limits, not all "safety-based limits" are actually safety-based, and I'm pretty sure you've misidentified the safety concerns in this one.
Its fun to do, it makes sense and was easy.
And your potato example is also shit. Being able to buffer a higly complex and easily disruptable supply chain for things you need to survive is smart not stupid.