Sure, it doesn't create long-lived waste, but it's a big stretch to assume that fusion reactors will be cheap. Even if you assume that the fusion part is cheap

Sure, it doesn't create long-lived waste, but it's a big stretch to assume that fusion reactors will be cheap. Even if you assume that the fusion part is cheap, you still have to convert the energy to electricity or at a minimum mechanical work (unless you're using the process heat, which is admittedly a possibility for a fair bit of current demand). Steam turbines aren't exactly cheap to build. Yes, there are alternative energy conversion possibilities for some possible fusion fuel cycles, but as I understand it those fuel cycles are much more difficult than D-T fusion and therefore are even further away from being a practical power source.