Our reason for going all in with GCP was the k8s. We've been using GCP for 2+ years. The trouble we have is with stability and so many of the features being constantly rolled out.
Our experience was that K8s cost more on GCP than AWS.
Just on LoadBalancers alone, you have tons of tricks that are specific to GCP implementation. And we needed a few extra because you couldn't run all the features we wanted on 1-2 per cluster. For example, we have a 3rd party that required all our requests to always originate and respond back from a fixed IP address. We could only pick one not a range, not a list. This was a hard requirement. The service was important so we had to do it.
It took our team several days to find how to do it using online documentation and support. Tech support was useless. We had one guy in our team that spent 2 days on the phone with a paid, local GCP implementation partner trying to get this problem sorted. Nothing came out of it other than being pitched on our dime a lot of services and architecture we didn't need. Eventually we figure it out on our own. I don't even remember speaking about this when we transitioned to AWS.