The US federal budget in 2024 had outlays of 6.8 trillion dollars [1].
nVidia's current market cap (nearly all AI investment) is currently 4.4 trillion dollars [2][3].
While that's hardly an exact or exhaustive accounting of AI spending, I believe it does demonstrate that AI investment is clearly in the same order of magnitude as government spending, and it wouldn't surprise me if it's actually surpassed government spending for a full year, let alone half of one.
It is clearly not in the same order of magnitude