For this context with Amazon though, prime is totally different in the EU than the US.

There are few countries with Amazon (eg Germany) and thus for most the benefit is that prime only gets free shipping on smaller orders that wouldn’t qualify normally, and faster processing in the warehouse. Maybe you get your shit a day or two earlier.

In the US it’s next day vs a week.

Point being there are far fewer prime accounts in EU so Amazon likely doesn’t care if they can’t discount as “deeply” as in the US.