D-H3 and H-B fusion release their energy in a form that can be extracted electromagnetically, with no detour through heat and turbines, so at least in principle could be cheaper to use than fission, unlike the D-T fusion that ITER etc. target.

There are projects working on these. They have much higher activation energy, so are harder to make happen -- for hydrogen-boron fusion, much, much harder. Helium-3 is scarce, effectively available only from decay of tritium, all of which has to be synthesized, then it needs to decay, with a half-life of 12 years.