@hosford42 @Minimac @GhostOnTheHalfShell @benroyce
It's not just a matter of "convenience". Amazon has built an empire where most 3rd party sellers pretty much have to go through Amazon's marketplace, and most consumers have a hard time finding somewhere else to buy much of the stuff they want/need.
When you do find a company online that you even have the option of buying from directly from their site (instead of just being directed to Amazon), you may be surprised that the item you ordered still arrives at your house in an Amazon box after all.
Buying at local stores is not much better since it's mostly down to a few big box retailers of each type (whether hardware, books, whatever). and most of their stock is not in the store but has to be ordered and delivered.
The options to buy from alternative sources are few and far between. This is how it is now. It's not just a matter of being convenient or inconvenient, but in most cases a matter of buying the item or not buying the item.