They are just like TCP/IP for a purchase from china, with buffering in the US, chunking, retransmit and guaranteed delivery.
You can probably be more efficient with UDP from china, but you could lose packets.
https://www.amazon.com/s?k=grip+strengthener&rh=n%3A14333021...
I will no longer use Amazon for anything where I actually care about quality or getting a legitimate product.
A few weeks ago I ordered the same USB charger a second time and got a different (but similar) item altogether.
Never shopped there before but finally bit the bullet and made an account.
Deposited $300 gift card. Amazon blocked my account completely (can not even contact support) and not long after got an email telling me it's due to sanctions suspicion and they require full KYC (including proof of residency and employment!) before I can ever see my $300 back again. I really don't have the energy to fight them for it...
Still asked a friend with existing Amazon account to order it for me. The seller cancelled the order saying "out of stock".
Our thesis is that seller is a money laundering front without actual product. Somehow Amazon's not closing their accounts, though....
If amazon is overpriced, the item might not be available from other channels/requires lots of work to get.
Another (related) point is that amazon is less risky than other options. You can usually get something cheaper from ebay/alibaba/banggood/etc
Somebody always has some nitpicky example, but in my experience amazon has reliable shipping and a predictable low-friction way of getting a replacement or your money back if something goes wrong.