I think this must be a consequence of where you live. I live in Santa Monica, and literally 100% of my Amazon packages have arrived on the day Amazon originally

I think this must be a consequence of where you live. I live in Santa Monica, and literally 100% of my Amazon packages have arrived on the day Amazon originally said they would. I order probably 1 item from Amazon a week on average and have lived in Santa Monica for 4 years. Thus around 200 items and I literally can't think of a time when the package arrived later than advertised at checkout except one Christmas.