I don't understand the discussion surrounding the cost of nuclear, talking about it being non-competitive.. When the alternative is what? Unleashing series of c

I don't understand the discussion surrounding the cost of nuclear, talking about it being non-competitive.. When the alternative is what? Unleashing series of catastrophic events due to climate change? which will have an unbounded enormous cost on societies at large. We've seen already what harm this type of thinking (cost-effectiveness of health systems, worry about costs of closing travel) is causing thanks to the Covid19 example.