Why, when we know, or are fairly sure that perpetual motion is not possible, do we continue to pursue fusion?
A perpetual motion machine would be like an engine that requires no energy input.
We know it isn't possible.
Fusion, would be like the sun with no gravity.
Why do we think that is any more plausible, than an engine that requires no energy input?
Fusion looks to me like modern day snake oil.
I would love to see such magic actually work, just like anyone.
But common sense says we never will, and common sense says investors are easy meat, for modern day snake oil.
Perhaps you will accept that most actual physical technology was preceded by mathematical theory.
Maxwell's equations predicted radio waves, and the speed of light, long before we ever achieved physical means of demonstrating them, for example.
And we know there is no theory predicting an engine which requires no energy.
Do you know of any mathematical theory predicting fusion, without the gravity of the sun?
If not, then why should you believe in it?
The improvement you mention in efficiency, is like improving the efficiency of a demo of an attempted perpetual machine.
The net gain in energy might approach zero with more and more tweaks, but it can never be positive.
Imagine if even a fraction of the money that has been spent on fusion, had been instead invested in construction of solar infrastructure.
No-one would be interested in fusion now, it would have been long consigned to snake oil. Our planet would be a much happier place, we would finally have achieved Kardashev 1.0
You might know the phenomenon of bullshit jobs.
Bullshit industry, is industry that creates bullshit jobs.
Bullshit science creates bullshit industry, and a dying planet.
It is such a waste of energy, and life.
I don't say that with any sense of triumph, just sadness. It really brings tears to my eyes to have to say it.