Why would any startup shackle themselves to AWS or any cloud when it's not portable?
Lambdas, in particular, seem like the worst idea in the history of ideas. Once your org adopts them, how do you keep track of these mysterious, business-critical pieces of functionality? How do you ever plan to port them to something else? It seems like you become an Amazon customer forever.
I am incredibly skeptical of cloud at this point. If the other infrastructure and platform concerns of OS upgrades, patches, etc. were handled in an automated way, I'd strongly consider running Kubernetes on bare metal. Data centers and colocation all the way.
I'm eager for self-management of k8s, DBs, Redis, etc. to be automated with tooling. On-prem, but easy to maintain.
edit: wow, from +3 to 0 after an hour. I maintain that I articulated my opinion well in an unbiased way.