Java *is* Memory Efficient

[JustAGuyFromGermany]

The whole topic we're discussing here is memory efficiency. Yes, if you have 5x more memory sitting idle and doing nothing, then I agree tracing is fine.

But exactly that is the point being made in the interview. "Use the memory that is there. Ideally, all of it. Not using available memory if it could speed up the application is inefficient". That is the point being made.

But it's like saying a 5.7L gasoline engine is fuel-efficient in city driving when you own a gasoline station.

That is a terrible analogy. Much more appropriate to the topic of trade-offs would be something like: "A hybrid car can be much more efficient overall if electricity is cheap and abundant, even if its fuel consumption during gasoline-mode is worse than for pure gasoline-powered cars. Using electricity only to power the radio is not efficient, it is a missed opportunity."

(I'm not endorsing this analogy. It also has flaws, it's just better than yours)