Mmm I think renewables could cover it without the need for fusion. I think there is one potentially big issue with renewables though. The supply chain for panels, wind turbines and batteries involves China quite heavily.* This year has been a hard lesson in the essentiality of energy security. Depending on what plays out geopolitically, renewables could suffer from deglobalisation and increasing hostility between superpowers. The low cost per MW of renewables obviously makes some supply chain assumptions. * This issue also pertains to fossil fuels, particularly gas infrastructure.

I also think that it is worth noting that renewables are a peaceful and ubiquitous energy source. Successful fusion would carry significant military advantages, which may cause a lot of disruption depending on who gets it first. This is always the way when someone develops a denser energy source.