Nuclear power successfully decarbonized almost the entire French electricity grid. The only case I know of of a large industrialized country without heavy hydro resources managing to almost remove fossil fuels from electricity generation. Maybe it's expensive (still less than in Germany which chose NREs, coal and gas), but it's also the only solution proven to work.
Yet a grid scale replacement for coal/gas using NREs still failed to materialize in the last decade. NREs definitely help with decarbonizing (and pushing NREs is better than doing nothing), but for some reason countries deploying NREs never seem to retire almost all fossil fuel production from the grid.
It is simply economics. In most grids the renewable penetration has been low enough to not warrant any storage, or they have hydro to balance it in for example Portugals case.
Now the battery revolution has begun and gas is being forced off the grids.
