Didn't knew France had such good benefits, so far here in Belgium, we also have family assurance, but that only count to the workers family, meaning partner and children, but doesn't count healthcare and such, some can have company cars and bonus cheques, even pension savings for the worker. Geuss even Europe is united, countries still have different benefits. I know we can pay for our own healthcare covered by various companies and funded by the goverment, even put whole family in one healthcare company, but I never knew there were jobs that would give healthcare benefits on top for a whole family like mother, father, employee + partner and children, here it more assurances for family and life assurances if dangerous job.
To be fair the "mutuels" are really cheap as they only have to cover something like 20% on average of leftover cost after the universal healtcare system we pay with our taxes. And it's no guarantee to be able to put your parents on the mutuels it depend of the contract, but it's common enough I knew about it off hand. The bulk is still partner + children though.
What usually happen is big company can negotiate by going to the negotiating table with thousands of potential employee so they can grab as many benefits as they can, and while it's not that much of an insentive to for a job, the best mutuel are always nice to have.
You can negotiate to have your parents on a mutuel you contact yourself but in general it's going to cost you more then if you're not doing that, or if you're not using company mutuel. Most people don't really use the mutuel for their parents, it's mostly those whose parent's are unable to care for themselves that do.
Just about the only thing I had to pay in the last ten years must amount to around 200 bucks total, for two hospitalization (round 20 bucks each), some physiotherapist session as well as one or two medicine not fully covered by both healthcare and mutuel. And one medical RDV with my doctor where I forgot to bring my carte vitale and never went aroudn getting reimboursed xD Never had to pay for dental, glasses, common medicine or medical visits. Even Psychological supports are free if you know where to look for...
But as a rule of thumbs Healthcare is nothing to worry about in France, or in Europe in general anyway. Country differ a bit but unless you're an orphan vegetables (in which case you're probably dead anyway) chances are you're not going to have to pay much out of pocket if anything to get you're health in order. Still there is a reason why the WHO rate France as having hte best healthcare system in the world xD
Far far away from the nightmarish story I keep hearing about the otherside of the Atlantic that's for sure XDD