Oftentimes I'm buying maybe a tool or a part or something like that which isn't necessarily available in my local hardware store.

Having a predictable delivery date for that on top of it most of the time being way faster than anywhere else is really nice. If I buy some of these somewhere else I might wait weeks for a small part due to logistics issues or low availability compared to Amazon

Not all purchases are things that are just consumable/materialistic. I find most of the time the stuff I buy on Amazon nowadays are things like this, where I want something I need but can't easily get locally or am too busy to go out and get during stores hours.