People love to say it, but when we had GSuite issues at my previous workplace we spoke to GSuite support and had a resolution quickly. When we had GCP queries we spoke to our account manager who gave us a technical contact who escalated internally and got us the advice we needed. When we asked about a particular feature we were added to the alpha stage of an in-development product and spoke with the team directly about that. I've got friends who have had various issues with Pixel phones over the years and they just contact support and get a replacement or fix or whatever.
Meanwhile I've seen colleagues go down the rabbit hole of AWS support and have a terrible time. For us it was fine but nothing special, I've never experienced the amazing support that I've heard some people talk about.
We were a <100 person company with a spend quite a bit less than many companies of our size. From what I've heard from YouTubers with a million followers, they have account managers and they always seem to encourage talking to account managers.
I should've qualified what I wrote, but what I mean is that no matter who you are, if you don't know someone there and aren't paying them money, there's no way to communicate with humans there.
It's like companies that won't let you sign up unless you give them a cell phone number, but not only do they not have a number themselves, they don't even have email. Or, for companies like Verizon, they don't have email, but they have phone numbers with countless layers of "voice assistants" you can't skip. It's a new way of "communicating" that's just crazymaking.
In this case, you point to the hypocrisy of being uncontactable but demanding your contact details, except that Google does provide support to customers, and in this relationship they are essentially a customer of your CT log, and given the criticality of that service they rightly expect the service provider to be held to a high standard. I don't think they're holding you to a standard that they themselves wouldn't agree to be held to for a service that critical. I've got to make it clear that this is my personal opinion though.
As a previous Google Cloud customer, we got pretty good support and responsiveness to outages. The details of any SLAs will vary by customer and contract, but there's accountability there.