Why would the odds concentrate only on the other unopened doors? Removing doors from the list simply increases the odds of all the remaining doors, including the one you chose.

Imagine that at any point in the door-opening process, you could decide to switch your choice for any of the still unopened doors:) According to your logic, the other doors would always hold better odds than your original choice.... but they don't. Because after switching choice and then removing another door from the list (in round 3) using that logic your original (now discarded) door choice would then have to have risen in its odds and your current door not :)