I went to Thunderbird - and had a number of people I'd met from other countries during my program - Guatemala, Japan, Canada, etc. None of which were in IT but none of which had any issues, as you described, finding work anywhere they wanted to live.
I wasn't picky about wages, I'm fluent in Spanish, and have worked abroad on behalf of a US based entities - so moving wasn't my issue.
In observing the workplace abroad, I with exceeding rarity never came across Americans working abroad, and never did I see them working in IT.
So I'm not quite sure what the deal is/was. It felt like a latent discrimination or paranoia of American IT workers held by foreign nations as I tried in vain to find positions in places like London, Paris, and Hong Kong - where plenty were advertised, but none would bite.
In contrast. Your observations are absolutely something I experienced as well. In my traveling and working abroad - 3 month consulting stints mainly - I met tons of people from around the world - like you said, France, Ireland, Senegal, South Africa, Argentina - and more - all working in similar capacities as I'd desired on a full time basis. At first I thought it was me, but once I realized ALL these places I came into contact with had NO Americans whatsoever in IT, I realized it wasn't about me, and there was something else going on.
What, precisely, that is. I don't know - that was back in between 2009 to 2015 when I traveled to around 20 countries in total, half representing a US/domestic entity in a consulting role I was looking to jump ship from to land abroad.
I have no logical explanation for it, and why it's so easy for someone - say a really good friend of mine from Guatemala - to get a job in Germany at Mercedes Benz as an industrial engineer.
Like I said. It's either something related to a latent discrimination of American IT personnel, that may carry over to other fields.