Amazon is slower than pretty much everyone else in Germany, and it's been like that for literal decades. To get almost universal next-day delivery nation-wide a shop needs to do exactly two things: Have the parcels ready by evening, and not be located in the absolute boondonks (which would mean two-day delivery).

Amazon, unless when ordering via premium shipping (included in prime but not worth it for that), takes days to even pack the parcel. Then they can spend a day or two sending it from one of their logistics centres to the other until handing it over to the actual parcel service.

What they do have going for them is the mindbogglingly huge selection. Pretty much the only upside, if you need five small things from what would be five different stores each having their order minimums for free shipping amazon is the sane choice.