Well it does not work that way in reality.

Legacy apps asummes a certain degree of reliability from the underlaying infrastructure. This assumption falls flat on its face in the cloud. Netflix wouldn't have needed to develop Chaos Monkey if this wasn't the case.

Secondly leap to cloud native never happens because no one wants to take the pain once it works even barely. Any issues can be pushed onto Infrastructure team. It's pure and simple risk avoidance.