people who say the 30 years thing say it generally implying that the failure has been due to humans underestimating the difficulty. when in reality, this is not a justified position, given the lack of funding for fusion. now that we have the tailwinds of improved tech and more investment and unified desire to address climate change, the "30 years away" assumption seems likely to capitulate if anyone is continuing to make it today, as the OP did.
> people who say the 30 years thing say it generally implying that the failure has been due to humans underestimating the difficulty. when in reality, this is not a justified position
It was very much a justified position. Humans did underestimate the difficulty. Specifically, codes for predicting behaviors of plasmas routinely gave overly optimistic estimates for what would be required to produce net power, leading to numerous experiments that produced orders of magnitude worse results than predicted. Basically every time a more powerful fusion experiment was built, new instabilities that we were previously unaware of (and thus the simulation codes couldn't possibly account for) were discovered. Fusion funding was initially abundant but dried up after repeated failure.
It’s unjustified because that is one of two variables: difficulty, and funding. Once funding dried up it became a determining variable. As we now see, progress has resumed as funding has returned. The “it’s always 30 years away” trope is backstopped by the assumption of low or declining funding.
Nope, one variable, funding was completely irrelevant. All the funding in the world can't give scientists precognition. Progress was always being made, if you look at a plot of reactor performance by year, it's a straight line from the 50s to today. The reason that fusion was 30 years away and always would be is because the knowledge gained revealed our ignorance - we were discovering new issues as fast as we were solving the already discovered ones. That's the problem with cutting edge research - there is no way of knowing ahead of time what trouble you'll run into.
Again, the progress didn't stop because funding dried up, funding dried up when it became clear the progress didn't matter. Fusion was appealing at first because it seemed easy, and easy things can typically be done economically. As soon as it became clear that fusion was much harder than initially believed, the hope of building power plants that are economically competitive with more mature alternatives was dashed. New startups can make all the claims they want about how their technology will succeed where others failed, but the fact is until they've actually succeeded, it is impossible for them to say they won't run into unforeseeable problems between now and then. Anyone claiming otherwise is lying.
https://upload.wikimedia.org/wikipedia/commons/a/ab/U.S._his...