The same happened to me. The French megacorp I was working for told me that my diploma level had a wage ceiling that they couldn't break. They offered to pay for training so I could get the required diploma in parallel of my work over a year or two. That was actually a very decent offer, but I was fed up with studying at the time so I just left.

Now I'm working in the USA where nobody cares. I don't consider myself a rocket scientist, but it's still quite sad for France to see all the comments about other French people that were similarly pushed out.

Last time I went to a meetup in SF about tech work in France, one of the French employers advertising there answered a question about the FR/US wage gap with "we aren't looking for mercenaries", essentially trying to fault workers' character for daring to ask for more. If I ever go back to France, it will be with solid plans on how to work remotely for a foreign company if the situation hasn't changed.