Various other countries do allow you to purchase various prescription drugs which are considered by the US to be unsafe. It doesn't cause any serious harm.
For example, Iran does not have an epidemic of dying women due to OTC birth control.
There are a lot of prescription drugs and a lot of edge cases. I think the Pill is a prescription drug in the US because it can be used to have a chemical abortion which is a seperate issue.
You can probably find a fairly large number of drugs that could become over the counter and every year many make that jump. However, antibiotics sould not fall into this category.
For example, Iran does not have an epidemic of dying women due to OTC birth control.