> Many countries have parliamentary systems and manage to be stable and working democracies. Many more have mixed systems which are much less forceful than France and also work fine.

And over the 70 years of the 3rd Republic and 12 of the 4th, stable and working are not labels that could be applied. The average length of a government in that period is around a year, with many being in power even less than that.

https://fr.wikipedia.org/wiki/Liste_des_gouvernements_de_la_...