No, it's about economic return on investment. Massive centralized power stations are a hard ask for capitalists, too much money sunk in for too long before return, too easy to disrupt by NIMBYs and Greens after decades of accumulated regulation. Fusion being successful does not mean it will be any more profitable than fission (almost certainly less for many years or decades), though there is the possibility of Democrats dumping in gigantic sums of government money. Unlikely though, because what Greens really want is reducing populations and lifestyles, not making existing or higher consumption clean.