I have a lot of information about how the services are functionally working underneath (under NDA, unfortunately) and what their limits are, they even informed us of their recommended course of action based on what we're trying to accomplish, they even invited me to feedback on their roadmap to understand what features are most desirable and even what UX patterns made the most sense to me, personally.
Of course, we were paying for enterprise support, but even during pre-sales they were giving us this information, I.E: when we were onboarding and before we had a contract in place.
We had an enterprise support contract with AWS too, that was the blessed provider at Ubisoft, but all I ever saw from them, upon multiple requests for technical assistance: was a dude telling me S3 is essentially magic, and that there's no such thing as a capacity limit in their cloud. Given that I managed to hit capacity limits in Googles and Microsofts Clouds pretty easily, I'm not sure I believe them.
I'm going to guess you're in North America? it feels like people in NA get a good support experience with AWS; however it's my experience that Europe gets absolutely shafted.
I believe the EU is following what america does in this regard, perhaps because of some potentially misplaced thought that the America is doing best practice. (or because Americans lead the world in software, so all software tends to support AWS natively).
He came back to visit us in Sweden 3 times because we kept asking for a technical contact to explain things for us.
I work for a US company now that's on AWS, the experience is very different from that.
The support team I deal with has always pulled in the actual devs from AWS if we have a particular question about a service. In terms of understanding our product we send them diagrams and they are well informed.