What purpose does adding oil/butter to thin pancake batter serve?

While I understand that adding melted butter or oil to thick, American-style pancakes improves the texture/crumb of the pancake, I have been wondering what the impact is on thin pancakes. Here are some example recipes of the style of pancake I mean: one, two, three (interestingly this third link is a vegan recipe and calls for the most oil by far).

I’ve read in some places that the main reason is to reduce the chances of the pancake sticking to the pan – but this seems easily avoided with the right equipment and technique anyway.

So what function is butter/oil serving in these recipes? Is it still a textural thing, as with thick pancakes (and if so, how would the texture be different with or without the oil)? Is it about the non-stick issue? Or is it just a flavour thing? Given the massive variance in amounts of oil I’ve seen added to otherwise similar recipes for this style of pancake, it would be useful to understand what function the butter/oil is truly serving.