Better in every regard including -immediate- costs, maybe. If we go worst-case climate change in 40 years, not putting massive development into fission and fusion power will clearly become the most costly mistake we've ever made as a species. Yes, we've got some promising renewables, but they are coming in the eleventh hour and it may be too late. We could have nipped this in the bud half a century ago. Your style of reasoning has been trotted out as a common-sense justification not to stave off the literal apocalypse for all those intervening decades, and here we are.

I don't think this can be overstated enough. Yearly budgets and disasters like Chernobyl and Fukushima are important, sure, but they're on an entirely different tier from what we're about to wreak on ourselves. We're evaluating the risk of these technologies all wrong. Accidents and sacrifices would have been worth it. Even nuclear proliferation leading to all-out nuclear war would have been preferable to what we're about to experience. And that is truly harrowing.