First, I wouldn’t count the vocative but let’s not get into this debate. Counting cases, Russian wins until you include other balto slavic languages or even Uralic ones.
Fancy is a very subjective term. Auxiliary verbs are fancy in their own way. From an orthographical viewpoint, French is quite fancy with all the silent letters, the way vocals are pronounced and stuff. French had like one spelling “reform” and it was like let’s make it more obvious we decent from Latin. Grammar wise it’s just like the other romance languages from what I know. They once got rid of the silent <s> and put a “gravestone” on the letter before (^) that has no other meaning than here was a silent s. Wouldn’t you call that fancy? Who would call it fancy? Mwa Moi!
Meh, as a native Dutch speaker auxiliary verbs feel really utilitarian to me, and not particularly fancy - like you said, that’s highly subjective.
As for cases, I didn’t say Latin or German had the most, but just that I think they’re fancy and that Latin has them while French doesn’t.
So you speak a V2 language like me? I’m German btw. Let me give you an outside perspective on auxiliary verbs in continental western Germanic languages:
The verb comes in second position (hence V2). Using an auxiliary verb moves the content verb to the very end of the sentence. It totally messes with the syntax.
But that’s besides my point. My point wasn’t that French auxiliary verbs are fancy but that fancy can me many things, in French it’s the spelling and pronunciation. Cases aren’t fancy, at least not the German or Latin ones. The slavic cases are a different story, in my objective opinion.
Haha I decline your proposal not to get into that debate: the vocative is a grammatical case. Maybe not every noun can be put in the vocative, but it’s definitely one of the cases. Even the locative is a case, even though only a couple of nouns use it.
To be clear, in general the vocative is a case eg in Czech and other balto slavic languages (except eg standard Russian while colloquial Russian is developing a new unrelated one).
In Latin tho, it’s more a relict. Other cases have relicts, too, still I wouldn’t say Latin has the locative.
I would argue that being a relict is a spectrum. Technically, it is a case with many syncretism to nominative, since it is obligatory for those nouns. In the context of LAtiN hAs sOo0 ManY cAsES, it’s not.
The Ohio State University seems to think these are both cases: https://classics.osu.edu/Undergraduate-Studies/Latin-Program/Grammar/Cases/latin-case .