> Isn't that literally supposed to be the sales pitch for the cloud? Get away from the infrastructure as a whole so you can focus on code, and let the cloud providers wave their magic wand to enable scaling?

Clearly there are limits even with the largest cloud providers. You'll have to engage a bit of critical thought in to whether you're going to get near those limits and what that might mean for your product. Obviously that's easier said than done, but you could argue that the cloud providers are still giving you reasonable value if you can pass the buck on a given issue for x years.