The economic impact doesn't just come from the fuel to energy ratio. One of the biggest differences is also in the space required. Nuclear fusion reactors could eventually end up being very small - like smaller than an SUV.
Imagine the cost savings in miniaturizing electrical grids.
A small fission reactor is also incredibly dangerous and will always require exotic material.
A fusion reactor does not pose environmental risk and could eventually run on highly available basic elements for everything after the initial "startup" once the technology progresses.
What exotic materials? Molten salts and steel is most of it. These reactors have essentially 0% chance to have airborn escape of radiation.
An fusion reactors don't actually run on basic elements. The require a fuel that is specially breed. And when they operate they have radioactive materials that can go airborn.
This seems interesting but not especially impactful.
For me, the question here is: can we get our energy to cost 90% less than it did?
Don't get me wrong, I recognise that this is still a huge win (especially environmentally) and that it can have huge runway effects (eg. much more effective decentralization etc.) but it's quite interesting on how we can get these billions of people out of poverty first (or during).
if they can be that small then they might find unexpected use in long range spacecrafts or lunar colonies. you'd still have to build and lift the reactor out of earths gravity well.
Here on earth we could see them used to power container ships as well, which are some of the biggest contributors to greenhouse emissions as far as vehicles go.
[1]: https://en.wikipedia.org/wiki/Cost_of_electricity_by_source