Not all funding is equal. For example compare investments in the Space Launch System vs. Falcon Heavy. Investments in ITER are also fairly inefficient due to t

Not all funding is equal. For example compare investments in the Space Launch System vs. Falcon Heavy. Investments in ITER are also fairly inefficient due to the political strings attached. Countries get concessions in exchange for funding, which makes it logistically far from optimal. It's also a slow-moving behemoth which makes it difficult to incorporate newer technologies as they appear, e.g. improved superconductors. I think it would at least be a good idea to throw some more money at smaller projects that can iterate faster than ITER. Also, past funding is not necessarily equal to current-day funding. Materials sciences and computing have advanced, so we can build on technologies that simply didn't exist back then. One example is simulation of plasma instabilities.