If you convert natural gas to hydrogen, you can sequester the CO2 produced. The hydrogen production facility can operate 24/7, with the hydrogen stored and only being used when necessary. In this way, natural gas could continue to back up renewables (or back up renewables + short term storage) without CO2 emission, at a capital cost per kW far below nuclear plants.

(The same argument applies to "green hydrogen"; which would be chosen would depend on economics.)