yes, it's not very efficient output method even for fission, but it doesn't even apply to fusion imo.

the energy output of fission is mostly heat, so it makes sense to use it for boiling water, but the energy output of fusion is more diverse including neutrons and alpha particles etc. we're going to need some revolutionary ideas to capture most of the fusion output. it'll just get better once we have a working prototype. just like everything else we've invented and perfected over the years.