> The environmental argument
Which is an economic argument, too. It's merely not been priced in yet.
Yup. I guess we still disagree if nuclear is needed long term for Dunkelflaute, and for countries with darker winters.
It's one thing to use storage for overnight. Another if it's for a couple of weeks. And yet another for 6 months.
And take Sweden: Lots of hydro power yes, but where it can feasibly & economically be built, it already has. You can't expand it. And that's not even mentioning that all you need is a drought in winter, and you can no longer rely on it. Currently Sweden is backed by coal plants in Germany. But we need to plan for it being Dunkelflaute in Germany and Italy, at least enough to not have surplus for the nordics.
As for "it's always sunny somewhere", sure, but you need to get it there, somehow. Transmission is why electricity prices in Sweden can be "more than infinity percent" more expensive in south of Sweden compared to north. (electricity prices in the north has gone as far as negative), and is why data centers are built near power plants, or at least it's part of DC location planning.
If transmission costs were negligible then we wouldn't need to take power into account for DC placement. I have some rants about this related to how some DCs are away from population centers to save money on power, noticeably sacrificing latency to the actual end users.