Well, you might think that. Did you consider that you might be wrong and maybe Amazon actually has lot of data that you don't and they know it better?

Just a couple of examples.

I might have bought a hard disk drive a couple of days ago and realize that I actually want more so I can do backups (or I want to build a cute HDD tower with a Raspberry Pi).

I might have bought ear plugs for home, and decide a week later that it would be nice to have those at work, too.

I could have bought zip ties, only to realize that I actually want more in different sizes and colors.

I bought a pijama, it was delivered and I want to buy 3 more of those, so I can throw out my old ugly pijamas and not worry about buying new pijamas for the next 5 years.

I got headphones but they aren't quite perfect. I didn't issue a refund yet, but I know I'd eventually send them back and want to buy a similar headphone asap.