They have no upsides
Except the lack of greenhouse gas emissions, once up and running.
If we actually started developing them on any sort of scale most of those negatives you mention will be negated.
Flexibility, as in the inability to quickly ramp down, can be solved with storage or with generating hydrogen.
Sorry, I was replying to a comment about offshore wind in the EU.
Supposedly you’d set up some proper regulations, implement checks and balances but given the current US business and political climate; good question.