There is exactly one reason we spend $billions every year on Tokamak: it is a jobs program for high-neutron-flux physicists, to maintain a population to draw on for weapons work.
That is not to say fusion is itself a dead end; just that Tokamak is stealing the funding that could otherwise develop practical fusion power. E.g., the FRC DFD project shows every sign of near-term viability, but is starved for the small amount of money that would take them to fully practical power generation and also spacecraft propulsion.
The project is in "Phase II" development under NASA, and needs just $50m to get to a viable prototype -- pocket change for the Tokamak club.
I read a paper recently that basically said that the best bang for buck is to just work on better superconducting magnetic tape. Stronger fields make everything better, and the scaling law is cubic!
Even if such a tape is developed but doesn't lead to fusion, we'd have better MRIs and DC power lines as a side effect, so it's not even wasted effort!
We can still say that no amount of HTS tape, or of anything else, will ever make Tokamak hot-neutron fusion competitive. But that is not a reason to abandon HTS tape development.
The payoff would be worth it a hundred times over. Not just because of cheap, clean energy, but also because the earlier we start weaning ourselves off of fossil fuels, the better.
But did you notice my choice of words? I said nations, not governments. Governments do not represent their nations. They represent themselves. And they are made up of a small number of greedy, self-interested, mostly corrupt individuals looking out for their own personal benefit. They benefit from bribes (coughconsulting jobscough) from their "partners" in industry. The oil industry. The coal industry. The gas industry. Not just mining! Even power generation industries have a vested interest in delaying fusion as long as possible.
There is no fusion industry yet, and non-existent industrialists cannot pay bribes.
This is the essence of why governments are disinterested in the future. They're only interested in the bribes they get in the here and now. Oh, I'm sorry. "Alleged" bribes, I mean... perfectly legal donations.
Worse, the scientific bodies involved in the nascent fusion industry, like ITER, have become cancerous. They exist now only to justify their own enormous scale. A growing bureaucracy that benefits only from its own size, not in achieving its goals. Hence the plans out to 2050. The longer the better. Got to think about all the project managers that want to reach retirement age and start collecting that pension without ever having to actually deliver.