Is Amazon deliveries better or worse for the environment?

Amazon was in the news recently and one redditor was decrying the harm amazon deliveries do to the environment.. i was curious and googled and could find no studies.

Is it better for the environment? I assumed obviously no. But the more i thought about it , i think its prob yes.

For example if i want something from amazon..amazon orders it. Stages it outside the city then trucks it in to my local warehouse and the amazon guy delivers it.

If i were to pick it up myself. Walmart , for example, would order it. Warehouse it outside my city and truck it in to their various stores . Where i would have to drive and pick it up.

The difference is the mileage i drive to the store vs amazon driver. Would you rather have 100 ppl driving to the store. Vs 1 amazon driver delivering 100 stops

Lets say the store is relatively close, 2 miles. Thats 100 ppl driving 2 miles = 200 miles vs the amazon driver who drives prob 50 miles a day going house to house up n down the streets ( amazon /ups drivers, how many miles you drive a day?)

I cant imagine a scenario where 100 ppl would drive less than the amazon driver, unless those 100 are walking /biking.