In theory fusion power has a great advantage over renewables: it could potentially be ramped up in a short span of time (that is not possible with fission plants). Energy storage is still very expensive and is the main limiting factor for renewables. It is the main talking point for skeptics: what to do when the sun does not shine/wind does not blow.
Anyways, if they finally get it to work then it has the potential to out-compete every other power source.
BTW energy transmission over long distances is very expensive to build. Someone tried to design a solar power plant in Sachara to provide electricity to Europe. But it was specifically the transmission infrastructure build-out cost that killed the project.