Yes, probably, I mean I come indeed from a Grande école but since I've never actually worked in France, it's never really been asked for. And the few times when ranking was important (visas for Japan and Hong Kong), the fact that it's not well ranked internationally means that I got no exta points.

In the end, I do think that degrees matter less than what people think and that it's completely possible to have a good career without the school name or university name having much of an influence (obviously it's anecdotical and probably depends on the field). I do strongly believe that being saddled with lifelong student loans is probably more detrimental than the positive aspects of a degree in most cases (maybe with the exception of lawyers but the only those who can cope with the lifestyle)

The fact remains that most educated people are aware of the French approach to higher education and the exacting filter applied for entrance and matriculation.

As an example, in a previous job, I noted that the new French software engineer had come from INRIA and was a graduate of a Grand ecole. The fact that this resource went on to demonstrate well above average work and domain abilities was not a surprise to me.

So note that some of us do pay attention even if it is not mentioned during recruitment.

I absolutely agree that you can have a good career without having a degree (or a degree from the right school), but you will have a very tough time getting beyond a certain threshold. I understand it's very obvious in France for upper management and public/political higher positions that it's not merit-based. The same is true for most countries, with varying degrees of impact and obviousness.

But if you're not going for that threshold, you'll likely not run into issues. And if you're in niche-careers, it's probably true as well.