There really are locations where DNS resolvers don't honor TTL. For example, the public wifi in the last Hackspace in Munich I visited did not honour my 10 sec

There really are locations where DNS resolvers don't honor TTL. For example, the public wifi in the last Hackspace in Munich I visited did not honour my 10 second TTL. But in my opinion there aren't enough of them to justify not using short TTLs. It's their problem after all if they don't honour websites' settings: Then they will see downtime when nobody else does.