If you use the car the way tests use the car, the performance will be the same. The trick is you can't complete your daily driving needs by driving the way the test does.
For VAG this wasn't a case of the test not being quite the same as regular driving, it was VAG deliberately detecting a tests and altering the way the engine worked to avoid failing.
Intent matters. You can’t set out to cheat a test, succeed, and then say that it’s legal because you succeeded, any more than you can steal from a store by hiding an item under your coat and then say that it’s legal because you disguised it well enough to fool the guard.
If you think the test is bullshit, then you make that case separately. You don't lie about how you're passing it and then when caught say 'but it's the test's fault!'.