it's a way to get infrastructure built up. the tax dollars pay for bootstrapping of the ecosystem. it's actually smart in principle if you think about it, but obviously there's room for abuse and outright fraud.
Nuclear energy wouldn't even be a thing without heavy govt subsidies. And it keeps needing subsidies. No nuclear plant is economical without subsidies. (The operators admit this themselves.) In contrast, the solar and wind industry is eventually carrying itself without subsidies. In many parts of the world that's already the case since tech and market have matured.
By that time Germany cumulatively poured around a trilling euros into the green energy and still had coal power plants and 2x the CO2 per capita compared to France.
As of 2026, in Germany 22.5% of electricity still comes from coal and CO2 per capita is still 1.7x of France.
The hard numbers so far are extremely favorable towards nuclear. Roughly speaking you get 1.7x better results at a 1/4 of the cost.
Germany wasted enormous amounts of money on green energy and made very little progress.
Which country is more "green"? Which technology is more "green"?
When Germany started serious bets on wind and solar, after 2000, France didn't really add much nuclear anymore.
So, the comparison you are making just doesn't work well, no matter if one likes nuclear or not.
Instead they chose to pour money into wind and solar and ended up with:
* higher CO2 emissions
* higher consumer electricity prices
* all that for much higher implementation cost
The gap is massive. I think it's directly comparable: these are two neighboring EU countries, comparable in size, population and GDP. They made different choices which led to significantly different outcomes.