We could argue that startup salaries aren't the highest anyways, so if salary isn't too big of an issue if French startup can provide equity easily. It seems that when you exercise stock options in France, you don't need to pay tax on it until the options are actually sold[1][2], so that's a good thing for employee, no need to scratch your head with 83b elections and whatnot.
Regarding the lack of tech talent, there's still a lot to be done. France has incredible engineers, but those engineering schools are not focused enough on Computer Science, instead they excel in "old-school" engineering like Aerospace, Civil, Nuclear, ... . On the other hand, Free universities have Computer Science degrees, but they don't prepare the future graduates as much as the Engineering "Grandes Écoles" would in regard to core engineering knowledge. There are some attempts at schools focused more on Software Engineering, but I feel that they're more similar to longer bootcamps with a focus on projects, I think those who graduate such schools are trained to be good "monkey coders" (pardon the expression) but lack a growth-mindset.
[1] (in French) https://www.impots.gouv.fr/portail/particulier/questions/jai...
[2] (in French) https://www.impots.gouv.fr/portail/particulier/lactionnariat...