serious question, do people without amazon prime get 99% of the shipping benefits we get?

I live in NYC. So big city. Maybe we get more amazon network/distribution benefits?

But the thing is my friend sometimes asks me to buy stuff for him. He says every other time? No fees for him. Free shipping!

Wasn't that like 80% of the point of amazon prime?

This is what tipped me off: Every time he asked me to buy it for him, because he knew I had prime, I would check for him. But MOST of the time those items would cost ME shipping! Weird.

So I'm wondering, wtf? Prime's benefit for me is the free shipping. And so for this guy, if he is getting the benefit what seems 80+% of the time, like what do I have prime for?

Has anyone else talked to other people who don't have prime and seen this? I am also wondering if it requires you to be in a big city, cause that'd make sense. Cheaper for amazon.