If your argument would hold true, that load would already be taken by coal power plants which fill the same role. Gas peaker plants are substantially more expen

If your argument would hold true, that load would already be taken by coal power plants which fill the same role. Gas peaker plants are substantially more expensive to operate per kWh of electricity produced than base load plants. They fill an important niche, but do not provide substantial continuous output. Nuclear replaces coal, coal replaces nuclear. Renewables plus gas (or storage) replace both. There are other niches where gas is used to produce electricity, for example we have a gas micro power plant that produces both electricity and heat for the apartment complexes on the local compound. This too, cannot be replaced by a nuclear plant.