$13 per month per egress rule, bandwidth costs a factor of 100 more expensive than dedicated hosters, and costs for hardware 10x of what dedicated hosters offer.
I’m not sure what your definition of "more expensive" is, but compared to renting dedicated hardware (e.g., from Hetzner), or colocating, GKE is significantly more expensive.
Of course, if you’re on the scale of Spotify, you can get much better deals – but from what I see on https://cloud.google.com/products/calculator/, it’s not cost-effective.
That’s why I disagreed with the "GKE isn’t more expensive".
depends on what scale your at and the fact that your vendor locked, can't use GKE in other data centers