you use different pronouns ("vous" or "tu" - cognates to "you" and "thou" in English) depending on the relative status of your interlocutor (and other things)

Dunno about French, but I think that in most languages with such a system the V form is getting rarer and rarer. For example, in Italian the rule used to be that one only used “tu” with friends, family and children/teenagers (of course this is only as precise as one's definition of “friend”, but still); but nowadays one uses it with everybody except superiors and people obviously (at least a decade) older than oneself (with the weird result that someone in their 20s is more likely to be addressed as “tu” by a stranger in their 40s than by a stranger in their 70s). In English too, addressing people as “Firstname” vs “Mr Lastname” is roughly equivalent, and the latter is becoming rarer and rarer.