The big difference that makes the analogy not useful is that being the landlord of every corner spot in downtown means people face a high cost when going to a different vendor in a different physical location.

Amazon is a website, the cost of visiting a different website is pretty much zero.

Sure, but as Amazon captures more of the online shopping market... it gets increasingly more difficult to sell something to someone outside of Amazon (which is also why Prime exists).

The cost of not being on Amazon increases as Amazon's size increases. Is there a point where that becomes unfair?

Everything is life is unfair. The question is where does the government need to intervene.

In my opinion, not yet in the case of Amazon. As I listed, they numerous competitors, and one hardly needs Amazon to obtain their goods. It is trivial to throw up a non Amazon retail website.

At least I can think of many more businesses where consumers do not have an option and extremely high switching costs that need to be dealt with first. Such as a home’s wired internet service provider. That is an unfair advantage that needs the government.

I would say the iOS/Android duopoly is another big one.

The inconvenience of needing to go to a different website (which already exist) is not.