Because they are liars and they like to steal... It's happen to me... Being home says delivered and signed for... The worst part is that Amazon is aware of this...

Mine said "7:45pm - Attempted Delivery". I was here and so were two others. I was at my computer with a view out the front window... literally nothing goes down my dead-end street without me seeing it.
So yeah... these nighttime "attempted deliveries" are outright lies.
Here's the translation: The LaserShip guy driving packages around in his own car wanted to get home in time for his favorite TV show, but still had a bunch of undelivered packages in his car... so he marks them all as "Attempted Delivery". That's how they roll.

Because they always deliver to the wrong house, so ridiculous!

I complain to the vendors when the carrier obviously lies about the delivery. They will never know otherwise and they may eventually change carriers if they get enough complaints or have to replace enough orders.

One FedEx carrier pinned an attempted delivery notice on my locked back fence (don't think he bothered to get out of his car in the alley). It was an overnighted iPhone and I was at the door or nearby the whole time and would have heard if anybody was on the front porch, the designated delivery spot. I had a signed note on the door for them if I weren't there. There is no back porch or back door. Better than them tossing packages over the fence, as they also have done frequently.

Recently had an Amazon delivery by their own service, a replacement for yet another misdelivery to some other house's back door (I put LEAVE ON FRONT PORCH after my last name in shipping address). The replacement order was at least delivered properly, but the vendor was told it had been "handed to a resident". Except the resident was inside and the door was closed and there was no knock on the door. Maybe he left it with a squirrel who was just visiting?

You know my package dissapeared into thin air with these people