The point I was trying to make is that fusion makes sense, the only issue is actually doing it.

In contrast solar roadways and space based solar don't make sense. Sure you could build them. But it would never make sense to do so because there's always a better way to spend your money. It's never* going to make sense to build a solar panel into a road than just on a field. And it's never going to make sense to build space based solar rather than just Earth based solar + batteries.

*standard HN pedantry disclaimer