[ZeroGravitas]

We do, where it makes sense, like Iceland:

https://ourworldindata.org/energy/country/iceland#energy-mix

But, as it being listed as 'other renewable' hints, it doesn't make as much sense elsewhere, where generally you can just install more solar and wind and save more carbon/money that way, and leave worrying about windless nights till you've picked the low hanging fruit.

For example, the current US plan is that after getting to 95% carbon free energy, to switch the focus to electrifying more things that currently burn fuel directly, rather than worry about that awkward last 5% before they need to.