ITER is a technology demonstrator intended to show sustainable fusion. The amount of power it generates is lesser than it will require to operate. The physicist Sabine Hossenfelder has a great video on her YouTube channel that I highly recommend watching.
It’s also a large international collaboration, a study on the engineering challenge involved with building a fusion reactor and a way to improve the technological know how of some participants.
The truth of ITER is that the way the work is shared slow down the project considerably. It would have been much faster as a collaboration between the three or four countries in the world with actual hands on experience on large scale reactor building but ITER is first and foremost a political thing.
