If you've lurked on HN over the past decade you'll have seen tons of stories about how bad Google's customer support is. I don't think GCP's support is anywhere near as terrible as it is for Google's consumer products, but it does have a lot of room for improvement. If you work with a reseller, you'll get much much better results.
There are several GCP resellers that are really good and knowledgeable, and often are staffed by former Googlers that worked on GCP. The very first thing you should do if you've chosen GCP is to find one.