@N0ZB@mastodon.radio Yes, we use them too, but only for a few specialized applications, mainly to power spacecraft that can't effectively use solar panels like the Voyagers, Curiosity, etc. We don't sprinkle thousands of them around the countryside just in case they might be needed, then abandon them.
We also build ours from expensive plutonium because it results in a compact unit that produces a lot of power and little radiation. We don't build them out of waste cesium-137 and strontium-90 that produce lots of radiation and not much power.