> I dislike the wording "social contribution", as these are (mandatory) insurances that benefit the insured person in case of sickness, retirement, loss of employment, etc.

They benefit some insured persons. If everyone benefited equally insurance would not be needed as you could just take the money and pay the doctor directly. But even the expected benefit if you average out unpredictable health issues is far from equal as what you pay doesn't depend on your risk factors. That's what makes it a social contribution. And since you are forced to pay it it's a tax.

> Anyway, the current generation of retirees benefit greatly from it, so for them at least it was worth paying.

You mean the last generation of retirees. The current generatin of "retirees" is forced to slave away the remainder of their lives in the super market checkout and other demeaning jobs. Absolutely despicable outcome considering how much money the state sucks up.