It's not a win for the USA because one of their enemies gained influence in the region. It's really as simple as that, but:

The invasion also led to the rise of ISIS, which is widely seen as a embarrassment to the USA because they were supposed to be rebuilding a country and ended up allowing a large and deadly terrorist group to form under their noses.

And just to add on, there are literal losses as well. When the Iraqi army retreated from Mosul in 2014, they left behind a bunch of US supplied equipment that ISIS took control of. Iraq has "lost" at least a billion dollars of military equipment in recent years, most of which has been taken by ISIS and enabled terrorism: https://en.wikipedia.org/wiki/Fall_of_Mosul https://www.newsweek.com/us-military-lost-track-1-billion-wo...

"Iraq has "lost" at least a billion dollars of military equipment in recent years"

That's...one tenth of one percent of the cost (to the US) of the war.

That’s the wrong measure by a long shot.

If I lose a $2000 rifle, and that rifle is then used to massacre a school, was the loss a mere $2000?

If you lost a thousand $2000 rifles, then the loss was a "mere" 0.1%. Plus or minus an order of magnitude (or two).

I mean, like, you are implying the other 99.9% of spending on the war was harmless or salutary?

No. I’m just saying that they used the money that we lost to gain strength and power, and they used those weapons to kill us and many others. Gaining power and resources provided them with the ability to leverage that and grow even more, and to fund new criminal enterprises. Focusing on the relatively small dollar amount we lost to them initially doesn’t really capture the total loss.

I think this is getting into the same territory as the difference between owing a bank a hundred bucks and a hundred million bucks.