It’s hard to think of any other invention that has had that much money thrown at it, without ever having made a cent. The aeroplane, the automobil, the rocket engine, the computer, the fission reactor all required some R & D, but nothing like fusion. Most of those other inventions were making money long before they were mature.
There are two kinds of phycisists, those who are good at physics and those who are good at getting funding. Look at some of the rediculous projuect that have been funded, such as LIGO and the LHC and soon ITER, where governments have sunk billions into the project, only to be told in a billion page document how the negative outcome of the experiment was a great success, and that not finding gravity waves or Z bosons proves that we had it all wrong.
More funding does not make better physics, instead it requires a journey of the mind, by someone who dares to go where no academic goes, for fear of being rediculed by the pillars of academia.
Fusion will succeed, as a result of new understanding and not by building a bigger tokamak.
Steven