gcp cloud nat wasn't really used in the first itrations, it was only introduced at the end of 2018 and "private" networks were only a thing in like middle of 20

gcp cloud nat wasn't really used in the first itrations, it was only introduced at the end of 2018 and "private" networks were only a thing in like middle of 2019 and it is still not the default, especially not on gke (besides that cloud nat is cheaper)