The number is $20B for a "technology of the future" project because if you would propose a number 20x larger the project would never get started.

How are you going to justify $1.2 trillion to tax payers for something ephemeral that might work or not, all while their kids cannot get toilet paper in school?

$20bn is kind of "normal" in government spending and those numbers are quickly forgotten.

On the other hand, the yearly US defense budget is already half of that amount and the loud voices do not care.

I understood the 1.2-1.5 trillion number to be the cost of "fusion as a viable energy source" not the cost of ITER. ITER itself, to be clear, won't generate electricity. It's a demonstrator project that proves the viability of some of the technologies that would be prerequisites to an eventual successful electricity generation project. Its planned successor, DEMO, will be even bigger, and will be the first one that actually generates net electricity, but even that won't be geared towards commercial use on the grid -- nobody will ever build these things for commercial use, even if we get to the point more energy comes out than goes in, if they cost tens of billions apiece. Even if both ITER and DEMO go exactly to plan, multiple additional major technological advances will be necessary before the any of it is commercially viable.

Ah, maybe that's why it's taking so long...