From personal experience in multiple startups I can confirm that with regards to customer service and sales processes AWS is light years ahead of GCP. That said I have heard even better stories about Azure actually - apparently it is yet in another league of its own in terms of perks and actual service game.
A client once requested we file a support ticket with Azure to help deal with a performance issue my team was working through. It wasn't really all that urgent, but the client requested we use the highest urgency level anyway. So I filed our ticket.
In less than a minute I felt like my phone was being blown up by every engineer at Microsoft. And the messages they left made it clear that the fate of humanity hinged on resolving our issue within the next five minutes.
On top of that, the depth and intelligence of the support was downright humbling to this fellow engineer.
(At the end of the day, it turns out we'd screwed up and left debug logging on.)