> It is widely understood that you really can't compete with "as good as".
Sure you can, that's why there are hundreds if not thousands of brands of gas station. The companies you list are unusual exceptions, not the way things usually work.
Im not sure a gas station analogy really works. I use a gas station out of convenience (i.e. its on my route) and will only go out of my way for a significant difference in price. This means i go to the same gas stations even when there are others that are “as good as” around just because it’s convenient for me. Similarly if i already setup an account with Amazon and currently use Amazon i won’t move to an “as good as” competitor just because its an inconvenience to setup a new account, add billing info, add my address, etc… for no real improvement.
Sure you can, that's why there are hundreds if not thousands of brands of gas station. The companies you list are unusual exceptions, not the way things usually work.