This is exactly why you let private entrepreneurs do things rather than the government. It'll get done better, cheaper, and faster.
Actually you will typically only get two out of those three. Saying that there should never have been any tax spent on this is really not understanding what these entrepreneurs are doing. The reason that any of these startups are even possible is because of the huge amount of work which has been done on fusion in the past by governments. If none of that money have been spent there would be no fusion start ups because we would not have enough knowledge about fusing plasma to make any sort of even vaguely viable bid for investment funding. In addition some of the startups are actually get tax money to help them startup.
Rather than denigrate the government paid research that got us here you should be looking at a research system which is doing exactly what it should be and working extremely well as a whole. The, yes often ponderous, ship of state takes science on the long, risky and costly journey across a vast ocean of knowledge which does not appear to be very relevant to improving our quality of life until it gets within sight of something extremely useful. Then the entrepreneurs take over and rapidly construct a fleet of many different craft to get to the new shore which is now in sight. Most will sink without trace on the way to that shore but those that arrive rapidly explore and open up new territory for us all to benefit from.
So what we have here is a great example of the system working as it should. It's not a case of tortoise vs. hare and more a case of the tortoise carrying the hare until it is close enough to the finish that it can sprint across the line and win the race faster than either one could by themselves. Government research is slow and it is expensive but that is because they take on the big, slow and expensive research which private enterprise lacks the stamina to do. A successful team plays to each member's strengths and that's exactly what appears to be happening here. So don't complain - all those tax dollars you probably previously complained were wasted on fundamental research may well be about to be paid back ...and with a lot of interest if any one of these companies are successful.