I am a good teacher anywhere in the world, the location literally does not matter so that makes no sense.

but here teachers often take their students' success as its own reward, since they're already paid a living wage.

A teacher is a service provider. They are providing a service to people.

And the way it seems setup is that you can be a completely lackluster service provider and you get paid the same as the person trying harder and you do not get a choice in which person you get to be taught by.

So everyone loses in that scenario.

Why can't students and parents compete for the better teachers?

Why do the teachers nobody wants to be taught by get paid the same as the teachers everybody wants to learn from?

And why would anybody want to be a better teacher if it literally did nothing for them?

It makes no sense to say "They get a living wage."

Why can't I make more money for being better than my colleagues and having parents compete for my services?

Its just a really bad system and it makes no sense.