Also like AI, we have natural examples as existence proofs it is possible, followed by narrow non-generalised artificial examples, yet actually getting it working properly is very hard.
I kinda get the feeling there are a core of scientists who want to work on this stuff.
They'll work on it even if there is no hope of commercial fusion power, simply for academic kudos. Government's will fund it simply because there isn't much other blue skies physics research to fund.
60 years of high-energy physics breakthroughs! Not to mention material breakthroughs, laser breakthroughs, chemistry breakthroughs, control theory breakthroughs...
Today's high energy physics is at an energy some eight orders of magnitude higher than the temperatures in fusion plasmas. That's a larger ratio than between fusion plasmas and room temperature.