This things have been toyed with for a long time. They’ve found some optimizations, but it isn’t going to power anything large - even when scaled - without some kind of profound sci-fi leap forward. People have been talking about 1w of power for a loooooong time.

These things are going to be awesome for IoT sensors - active sensors that you can embed in stuff like concrete, soil, you name it. Where you can have something the size of a large pack of gum to produce 10mw and it’s OK.

But your phone? Nope. Not unless you want to attach an actual brick to the back of it.

RTGs of significant size - like in space probes- still produce tiny amounts of wattage. They build it up continuously and also make use of the heat to warm the electronics.

Oh, they didn’t mention the heat? Well… sure. At .0001w, it’s nothing. But 1000x to get 1w? Spicy meatball!

Nah, the future is neighborhood sized tokamak fusion reactors and good ol’ lithium.