You’re right that it’s large in an absolute sense, but any sector of the US economy is going to be large in an absolute sense. It’s not a very meaningful statement. Using percentages allows comparison to other items, which for some purposes gives a more useful sense of size. For instance, based on your numbers, AI expenditure is about 1/3 the total military expenditure. I tend to agree that this is less than I expected, and generally makes me feel a bit better about the (imo excessive) hype.
It's small as a part of the economy. It's huge as a completely new thing. The US economy in total has been growing something like an average of 2.5% over recent years. Something that is all-the-growth-of-the-last-year-in-one-place is pretty significant.
AI didn’t happen in one year. Netflix’s famous recommender system challenge kicked off in _2006_! And “Big Data” was all the rage ten years ago. The category “AI” includes these things.
