And I’m generally a nuclear proponent but one of the worst investments the French utility made was investing in the UKs reactor debacle at Hinkley C.

Per wiki, cost midrange is now 45 BEUR. That's ~14 MEUR/MW capacity (v. solar @ ~1MEUR/MW).

Ouch!

To make matters worse gas peaker plants cost approximately €1mln/MW as well, so at the cost of that plant you could have massively overprovisioned solar, backup gas plants and plenty of money for fuel to spare which you wouldn't be spending immediately, so it could be invested instead.

Yes, though gas plant install prices are 2-3MEUR/MW these days due to demand/supply.