America won Iraq and Afghanistan in a walk.

They didn't do a great job of nation building afterwards, but the actual war part was very successful.

You go to war because you want an strategic outcome you can't get with other means. I doubt the strategic outcome of the USA in Irak or Afghanistan was "kill a lot, lose not that many, leave the country in shambles, achieve nothing in return".

The strategic outcome in both wars was to replace the goverment for a friendlier one, and in both cases the USA didn't get it, not even close.

But if you view wars as an sport where people kills other people and the winner is the one who kills better/more, then war is declared over and "teams" look for another war to "play", indeed USA won both wars in a walk.

Bit lost here, to be honest - What exactly did the US win in these engagements?

You might make a case for increased control of and importance in the middle east for Iraq, sure - that declined somewhat after a forced fumbling backwards out of Afghanistan and tanked on contact with Iran, so if that was the take home stuffed panda prize to write home about it's been well and truly run over by a road train and left in a ditch.

Clearly big wins for the USofA PMCs, but that's a little more narrow than "America".

What the fuck are you talking about? Afghanistan was handed back over to the Taliban. That's a victory? Kill them and chase them for decades and then release a bunch of their prisoners and return control of the country to them and declare victory?