Single European datapoint, I'm currently in university.

In my country we have different levels of tertiary (?) education, as far as I can tell, lower levels of education have way more Snapchat use than Instagram. For most students of higher levels Snapchat is only used to share your night out with friend groups, but pretty much nothing else, while Instagram is used way more.

Not the case at all.

True here - the only people I use anything else with is work colleagues and parents. Everyone else uses Snap.