"Heavier-than-air flying machines are impossible."-- Lord Kelvin, president, Royal Society, 1895.
Impractical and impossible are two different things. You can make a heavier than air-craft out of paper, balsa wood, and a rubber band. Fusion reactors? Not so much.
The question is what's the most cost effective (including environmental damage) way to generate power. It seems like fusion may never percolate to anywhere near the top of that list. Fusion sounds great in principle, especially in troubled times - endless, free fuel! It turns out to be a pretty expensive free lunch, however, particularly compared to less complicated long term power generation technologies.
Fucking financial considerations....