Earlier quoted context omitted.
I think there is a bit of a brain drain, but it's also compensated by great engineers from poorer countries (Italy, Romania, Poland etc) migrating in If remote works, it won't really be a brain drain anymore, because they'll be paying taxes and spending their money in France :)
Is there any reason why the engineers from poorer countries will emigrate to France instead of the better-paying countries?
Romanian programmer here (I still live in Romania), I would choose another European country over a well-better paid job in the US in almost all cases, the reason being that that way I'd be closer to home, we actually have decent healthcare in Europe and the social contract as a whole is more robust compared to the US (it mentally helps going out on the street and not seeing the multitude of homeless people that I've read one can find on the streets of San Francisco), public transport is decent to exceptional and for me personally there's also the gun-control issue (or lack of it, more exactly), I really don't see myself living long-term in a country as gun-loving as the US is.