Personally, I would say a lifestyle that isn't just a thought experiment should answer one of
A) How do you support the current population of the planet like this?
B) How do you humanely reduce the population over time if you can't?
Obviously still value in thought experiments, but if you're talking about real life, ignoring those two questions gets a bit euthanasia/genocide-y pretty easily. "Every human being alive today not existing" should probably not pass the lifestyle test suite, right?